Lip
Chances: 5%
She doesn't have a big enough chance in my opinion and she is a very obscure character. In case you don't know, she was the star of her own game of Panel de Pon which was never released stateside if I am correct. Wait, Tetris Attack was released stateside and it was based off of Panel de Pon, but stars Yoshi as well as several other Mario characters instead of Lip and the characters in her game. There hasn't been anything too notable from Lip other than "Lip's Stick" being an item in Melee and Brawl and she was in Captain Rainbow which also has Little Mac and Takamaru in the game. Speaking of those two, she, like them, are considered retro characters (Little Mac did have a game on the Wii recently so... I guess he isn't so retro anymore?), but I've seen more demand and more popularity for Little Mac and Takamaru than Lip. She had gained some recognition from Sakurai from the already mentioned Lip's Stick being in Melee and Brawl and having her theme be remixed for Brawl as well as some Stickers from her game, but I don't think that he would want to put her on the roster.
Want: 5%
I don't hate her, but I rather have Little Mac and Takamaru than Lip.
Roy
Chances: 30%
Being a part of the infamous Forbidden 7, Roy was supposed to be in Brawl alongside Marth and Ike. If this was the Brawl era, I would give him higher chances. However, his ship has sailed and now he faces much more competition. With Marth being pretty much a lock and Ike being very safe, Roy suffers from competition from the more recent Fire Emblem characters such as Chrom and Lucina. He does have DLC for Awakening, so I guess this does help him slightly. He also has more demand than any character from Awakening which is pretty remarkable. He can easily be decloned and have an original moveset, so I don't find the cloning issue to particularly hurt his chances. Overall, with competition from other Fire Emblem characters, Roy would have to be pretty lucky to make it on the roster again for SSB4, though Sakurai can be a bit unpredictable.
Want: 45%
If this was the Brawl era, I would have rated my Want percentage a bit higher. When I saw that he wasn't in Brawl, I was admittedly disappointed. But now, I am not even sure if I want to see him in another SSB game. I don't hate the character like most do, but I would have some slight disappointment if he got in instead of a more potential character.
Professor Layton Prediction: 8.7%
He's third party right? While he has ties with Nintendo, he suffers from some competition.
Nominations:
Bowser Jr. 4x
Captain Rainbow 1x (he is from his own game in Japan called "Captain Rainbow" made by Skip Ltd.; since we are talking about Lip, I guess I feel obligated to give him a nomination)
EDIT: I changed my rating for Roy and edited my stance on his chances.