I think what's most disappointing for me thus far is the roster in general. I know I'm going to get flamed for my opinion most likely, but it is just that, my opinion. As far as newcomers are concerned, none of them really feel that interesting. I mean, so far we've gotten a walking manikin who is not even a real character as far as I'm concerned, a blue Peach (looks wise, I know she'll play much different), a guy whos "unique" quality is...punching? An obscure and irrelevant Pokemon, Mii Fighters (just...no), Marth with longer hair (at least Roy was a cool clone), and to top it all off, we have good ole' Palutena. Again, this is just my opinion, but seriously, we get a character that looks like Zelda with a staff, and is part of a series that has spawned a whopping two games. If you didn't think Sakurai was biased before, think again. What bothers me about having some of these characters is that it means they're taking away roster spots that could go to more established characters who are a part of more deserving franchises of representation, such as King K. Rool, Ridley, or bringing back Mewtwo. Then as far as veterans are concerned, I'm really disappointed that we're bringing back characters such as Toon Link, Lucario, Ike, and Zero Suit Samus. I would've liked Toon Link being back if they actually made him, ya know...different. But oh well. Zero Suit Samus is the character I didn't want back most of all though. Talk about slapping the Metroid franchise in the face. The fact that they think the same character in different suits is deserving of two different roster spots is asinine. Especially when people have been begging for Ridley's inclusion since what, Melee? We mine as well bring back Dr. Mario if we're going to have characters like her. Again, this is just my opinion, so please don't bash me for having it.
I can understand your frustrations, but allow me to maybe help you see things from a different perspective. I don't want to change your opinion, but this is what I think. While yes, maybe in terms of "content" and actual recognition, the newcomers are not all that spectacular. The thing with Sakurai is that, well, his philosophy with characters this time around is that he only wants to add people that he thinks would bring something new to table, that no other character can do. I think an exception here is Lucina, but that seems to be for the purpose of fanservice. Anyway, while yes, people like Rosalina may not be quite as well-liked or known as K Rool, or other classic characters, but I think that this time around, the newcomers are truly amazing in the different playstyles and abilities they offer, possibly even unlike any Smash before.
Megaman is almost entirely projectile based, and while Snake had a lot of projectiles too, Snake operated more on placing traps, while Megaman seems to be more of a zoning character. He has a projectile he can throw in all directions, a bomb he can stick onto people, and he can then rack damage on his opponents before the detonation by keeping them away with his unique jab, Metal Blade, or Charge Shot. Leaf Shield doesn't seem very good atm, but it's a protective shield that he can, again, use as a projectile if he wishes. So he has a lot of unique, awesome potential, and I didn't even cover all his moves. Villager is unique for his Pocket ability, and his Tree. His Pocket is like a reflector, but the awesome thing about it is that he can "reflect" it whenever he wants. Not to mention his unorthodox down smash that traps people, and his forward smash which can drop bowling balls off ledges. His dash attack is also a projectile. Then there's the tree. The Tree can be placed in about 2 seconds if you mash Down B, but it also gives you access to other moves while you prepare it. You get a watering can that you can push people away with, and the Axe is a really powerful attack, but lags after. So Villager seems to be all about patience, who has a lot of options and you gotta pick when is the right time to do what, while you keep opponents away with your Lloid Rocket. Little Mac is a character who has probably the best ground game of anyone in the series ever. As your opponent gets knocked further away, you'll have to think about if any of your air moves are worth throwing out to juggle or to keep the opponent on your terms. More than ever before, you have to think about risk vs. reward by playing Little Mac. Can this ground game make up for his air game? It's kinda like a reverse Melee Falcon in a way, b/c Falcon players usually stay in the air in Melee. I personally am looking forward to trying combos with Mac like Down throw, jump, nair, nair, land, and then maybe an up smash or something.
Since you mentioned her, look at Palutena. For starters, she is unique in the sense that she has 12 entirely different special moves! So right off the bat, you're bound to customize her to the point where you will find which of her special moves you like, and you can even change her moves based off of your playstyle! We haven't seen enough of her, but she has a humongous up smash like no other character, a shield bash move, I don't think we've had a character before that uses a staff, but her abilities look amazing! Then the Mii Fighters......dude.....c'mon.....so again, like Palutena, 12 unique special moves......x 3, but past that, how awesome is it you could potentially fight as and customize your Mii enough to fight as a character you never even thought you'd see in Smash? I'm already looking forward to playing as Walter White and kicking some ass, or Barney Stinson as a gunner, since he loves laser tag so much?? (How I Met Your Mother) The possibilities are endless.
My point with this wall of text is, I understand your frustration that maybe some cool characters you want aren't in the game. But Smash has always had an unpredictable roster, which is part of the beauty of it, but now, more than EVER before, it seems like Smash is taking inspiration from other fighting games by making these newcomers all extremely unique and offer something no other character can, just as Sakurai wanted. So, don't just look at the characters. Look at what they bring to the table!