Of course Tekken can be done on the Wii, like any other game. Developers know strengths and weaknesses of every system and if they want they can use it to their advantage.
Graphics is not the case; because Tekken (and any other fighter) was on PS1 and PS2 before and looked great on them (put in context of those generations) same it can look great on the Wii (compared to other wii games)
Controls, Wii Mote + Nunchuk is used for brawl and it works just fine, whats great about the Wii that it offers so many options additionally with Classic C or GC one.
Like Dark_Gh0st_B0y said any game can be made if Devs want to make it and know how to do it.
I expect to see at least one big fighting series on the Wii, maybe Virtua Fighter since it underperformed on HD consoles, and it seems that Sega hearts the Wii this gen
And Dragon Ball Z: TB3 plays awesome with motion controlls.
