Man...I had no idea this thread was revived - but I am so glad it was! :D *really late*
I'm still supporting Captain Toad and if Toadette is there to join along, then so be it!
Many do tend to stick to that one con about Captain Toad not being able to jump due to his backpack- however, I've seen an interesting idea around the net that might just do wonders for the good captain in Smash! The Note Block!
Why not just have Captain Toad tumble about in a hilarious way by bouncing on two Note Blocks that he spawns? It would toadally fit his character, and besides - characters like Ness have unique jump properties - why not Captain Toad? Seriously, Captain Toad is ready to fight dragons and large magpies that kidnap poor defenseless Toads. He isn't gonna let his backpack stop him for Smash!
Also alternate costumes open a whole new door for Captain Toad too. Blue Toad, Yellow Toad, and Banktoad all got similar uniforms to Captain Toad in Treasure Tracker, so it wouldn't be farfetched to have them in too as his colourations (with small tidbits like Blue Toad's glasses and perhaps a starbit hanging around Banktoad). Mailtoad would be nice too but there's the chance his colouration might be similar to Toadette. Add Toadette for the rest of Captain Toad's alts (perhaps a Classic Toad and Toadsworth alt too if we're lucky!) and we're good to go! Captain Toad, the Toad Brigade, Toadette, Classic Toad and even Toadsworth all represented!
Also that gender thing about the Toads is silly. :| Captain Toad and Toadette still identify each themselves with one gender, so there shouldn't be any issues about that at all.