No they aren't Bowser Jr's chances are much higher.
Yes because it's not like there's been many things that brought Bowser Jr's chances down... /sarcasm
1. All the characters that are playable in Brawl have independence. Bowser Jr can't truely function without his father and is comparable to Waluigi or even Toad (two characters that have already been deconfirmed for playable spots). The SSE videos have even shown us that Bowser is working solo and doing things that normally Bowser Jr would do for him. Should I also mention that all the Mario characters that are playable have been playable in at least canon game? Unlike Bowser Jr, Geno already has this base covered.
2. Pichu and Dark Samus have basically been deconfirmed and has basically shown that Sakurai isn't very interested in adding characters that are basically different variations of characters that are already playable. Bowser Jr's character design is a modified version of Baby Bowser and he was even his replacement in Mario and Luigi: Partners in Time. One may argue that this kills Wind Waker Link, Paper Mario, and Luigi's chances to become playable but unlike Bowser Jr, they actually star in their own games and are thus more important.
3. In all the canon games that Bowser Jr has been in, he's taller then Mario but slighly shorter then Peach so it's extremelly unlikely that this would change. Because of his body structure, he's naturally heavier then Mario and because Mario is the standard for height and weight, Bowser Jr would be close to being a heavy class character and, as we all know, Bowser is a heavy class character. Because of this, there would be very little that would differentiate Bowser Jr from Bowser when it comes to basic stats.
4. Of the characters that appeared at least once in Sakurai's journal, Bowser Jr wasn't one of them. These were the Mario characters that were mentioned: Toad (one entry: Peach's B attack), Koopa Troopa (one entry: normal enemy), Hammer Bros (one entry: assist trophy), Petey Pirhanna (one entry: boss), Mallow (one entry), and last but not least, Geno (five entries). The 290 entries that appear in this journal are the 290 entries submitted into the offical Brawl poll that interested/amused Sakurai and his staff the most. Obviously, this matters a lot and Sakurai has already told us about several characters that were highly requested but got the shaft: Little Mac, Deoxyes, Saki, and Waluigi. So far, all the characters that have become playable have either 1. were mentioned in Sakurai's journal at least twice (Lucas- two times, Diddy Kong- four times, Ike- four times, and King Dedede-five times), 2. were mentioned by Sakurai in interviews (like Sonic) and 3. appeared in the 2001 offical Melee Poll (Pokemon Trainer, Wario, Diddy Kong, and Metaknight were all the third most requested characters in their respective categories, King Dedede was the 4th most requested character overall and Pit was suggested 5 times like Geno). Obviously, Bowser Jr doesn't fall in any of these categories.
5. Bowser Jr's uniquess has gone downhill since his creation. Despite having the Shadow Mario form and the paintbrush in Super Mario Sunshine, he never truely fought with them and he strangely loses them after Mario Power Tennis. In the New Super Mario Bros, Bowser attacks uses especially generic attacks like jumping and throwing shells and is a mere miniboss that's the equivalent of Birdo or Petey Pirhanna (both characters who have actually appeared in more games oddly enough). In Super Mario Galaxy, you only fight him once and he attacks you from a flying ship. Keep in mind that like Waluigi and Daisy, he's been used most often as a filler character in the spinoff games. The fact that he has "Bowser" in his name doesn't exactly help his case either... I don't even have to explain why Geno runs circles around Bowser Jr in this category.
So, in the end, Paper Mario and Geno are really the only Mario reps that don't have a ton going against them. Besides, Bowser Jr will just be playable again like Daisy and Waluigi once the next spinoff comes out so, if you ask me, I'd rather have a character that I might not get the chance to play as again.
No!!!!! I'm gonna go kill myself...[/sarcasm] lol, I really don't give a ****.
