Oh, how I've been resisting responding to this thread.
I helped run a gaming club at the college I attended. And I ran SSBM tournaments for it. Sufficed to say, being stuck in a room for 6+ hours with fanatical smash players who play on the SAME level with the SAME characters with the SAME cheap tactics...tends to make you hate the game. Along with the people who play it religiously. And that pink bunny hopping around the room...
Anyway, I still retain some enjoyment of the game, deep down inside, and I am looking forward to Brawl's release. It makes me happy to hear that they reworked the physics system to get rid of those "gameplay features" like wavedashing (known as glitches to the non-fanatical world). What absolutely infuriates me, though, is the return of CLONES. Come on, HAL! You've delayed the game for how long, and there's STILL clones in it? It's acceptable that some returning characters would play similiar to their old counterparts, but Ganondorf being a Falcon clone AGAIN is simply unacceptable. I'd rather have a lineup of 30 unique characters than a lineup of 34 characters with 8 clones.
As for future games? I read somewhere on the forums of someone's idea for the single player mode. Something about travelling to each games universe and playing through it with respective smash players. I think that could work out to be pretty neat. But to be sure, if they release another iteration, I hope they incorporate some more gameplay ideas.