My "gut character" would be Samurai Goroh.
Samurai Goroh is one of those characters who isn't exactly likely to get in Smash 4, but I do feel as he is plausible enough to be in. I also feel as we'll be getting at least one C-rank character (in likelihood) in Smash 4.
I like to classify characters I could see getting in in three categories; A, B and C. A being additions I expect and would be surprised to be not see, B being less likely but still feel have good chances and C characters being ones that I don't expect to be in, but still feel could make it in. Take mine for example:
[COLLAPSE="A Class"]King K. Rool
Ridley
Mewtwo
Palutena
Takamaru
Little Mac[/COLLAPSE][COLLAPSE="B Class"]Toad
Dixie Kong
Roy
Mach Rider
Isaac
Shulk
Mega Man[/COLLAPSE][COLLAPSE="C Class"]Bowser Jr.
Ghirahim
Krystal
Samurai Goroh
Chrom
Saki Amamiya
Professor Layton[/COLLAPSE]You don't have to read the collapse below to understand my gut feeling about Goroh, but the collapse does tie in to Goroh.
[COLLAPSE="Said a lot more than I though I would"]If I had to predict a certain number, I'd say fifty-three. Of course I expect everyone from the A class to make it. The really interesting stuff comes with the B and C class characters.
B class characters I feel have the best chance are Dixie Kong and Shulk and I don't see them out of the roster for this game. Toad I would say is the least likely of the B class due to the possibility that Sakurai may not see him as fighting material, but I do feel as we'll get a Mario rep and I think Sakurai would pick Toad over anyone else. Roy has a good chance as well, although less so due to Chrom, but I still think he has the upper hand, so its hard to see him outside of the roster as well. Mach Rider's chances depends on if we get a 2nd retro rep and I have a hard time seeing us not getting a 2nd retro character (not to mention I don't think any other retro characters will get in aside from of course Takamaru). That leaves Isaac and Mega Man.
I think we'll be seeing three misc. series. One of them is Punch-Out!! and another is Xenoblade. The third one I feel will be between Isaac and Saki. Right now, I'm guessing Isaac mainly because his series is bigger than Saki and he is much more popular than Saki, but Saki has the advantage of Sakurai's interest in him and that could be enough to have Sakurai choose Saki over Isaac (especially since I doubt we'll be getting more than three misc. series). As for Mega Man, I support his inclusion above anyone else, even that of Mewtwo and I firmly believe that he is the most likely third-party character to show up (if we get a new one). Yet I'm starting to get a bad gut feeling about him (and a bad gut feeling about
Pac-Man
getting in), especially since I don't think Mega Man will get another shot at Smash Bros and I feel as if he's not the third-party (assuming we get one) revealed at E3 2013 that he won't get in. For now, I'm just hoping this gut feeling doesn't come true. So while I do feel as Isaac and Mega Man still have pretty good chances, they're the exchangeable characters.
The C class makes up the remaining characters I feel could get in. I think we could see anywhere from one to four of these character get in. I've already covered Saki, so there's that, so lets see the rest of them offer.
Bowser Jr. has the advantage of being an important part of the Mario series as well as being more accessible as a potential clone, which could help in making him a last-minute clone if Sakurai wants one. However, my gut feeling seriously doubts him or any other Mario character not named Toad.
Krystal is in if we get a 4th Star Fox rep. Sakurai is going to be looking at pre-Brawl stuffs and he's going to notice Krystal's strong popularity during that time. Krystal still remains decently popular, even if said popularity has declined. This could very well be enough to get her in, although I could easily see her be overlooked. More of a 50/50 character to me.
If we get a Zelda rep, Ghirahim is probably going to be it. He's a popular character that while a one-shot, is very important to the franchise due to how he sets in motion the chains of events in the Zelda series. The main problem with him, however, is that Zelda isn't likely to get a rep in the first place and he does have slight competition with Toon Zelda/Sheik.
Now for Chrom. My main issue with Chrom is that he's well... bland. There just isn't that much special to him, plus he faces a competition that's more popular (especially in Japan) and has been planned for Brawl and we know Sakurai likes to draw from previous game. That said, Chrom is in if we get a Fire Emblem newcomer and if DLC occurs, I really do think he'll be one of the selected characters since I do see him and Roy being planned for this game (but for one to be likely dropped). Of course DLC is not a likely possibility, else I would have put Roy and Chrom in A-tier likelihood since I don't see us getting characters DLC without both getting in. But we'll see on Chrom and Roy.
Professor Layton is my 2nd dark horse choice (Mach Rider is my 1st). This is mainly due to the president of Level-5 being interested in his inclusion along with he and Sakurai having connections. Seems to work very well as a Snake-like reveal, especially since most people would be surprised to see him in. He would take the place of Mega Man if I had to choose what other third-party to add just like Saki would take the place of Isaac if I had to pick a different misc. character.[/COLLAPSE]
And finally, Samurai Goroh, who seems to be the "middle of the road" character. He seems to be one of those character who doesn't necessarily have any big advantages over the others, yet he doesn't seem to have anything significant going against him. He's not a highly requested character, but still pops up enough to be noticed. F-zero is a franchise that is currently dormant, but I don't think Sakurai cares about recentness (and I do think he will look at adding a F-zero character one last time). While none of the F-zero characters are significantly different in importance, Goroh seems to stick out in being well-known (being Captain Falcon's rival). Probably the most important is that he doesn't share the same disadvantage as the others in C class. He doesn't have competition that could very well outclass him (like Bowser Jr, Chrom and Saki), he's not third-party (like Professor Layton), he doesn't come from a franchise where many are opposed to a fourth rep (like Krystal) and he doesn't come from a franchise where Sakurai will likely have super high expectations with characters (like he will with Zelda, which even Ghirahim may not fulfill).
I imagine that Sakurai has been looking at adding Goroh ever since pre-Melee (where he was featured in Melee's cinematic trailer, making many think he would be added). My theory is that had he not had such strong competitions, he would have probably gotten into Brawl. Now that with the pool having dwindled down significantly, it seems as Smash 4 is his chance to finally get in and I have the feeling that Sakurai will be bringing Goroh to Smash.
...I just totally pulled a ManlySpirit here.