Since it seems to be a fad right now...
Main: Pikachu
Secondary: Lucas, probably
I was initially going to main lucas, but when I was trying out other characters pika just fit my playstyle all too perfectly. He's got decent speed, a good approach (gogo fair and thundershock spam), his combos are awesome (gotten a couple 0-deaths so far, although to be fair they were more like 0-60 or 70 and then a slight pause while I go for another approach and
then a combo to death), and then between a more spammable thundershock, an amazing thunder, and a much improved dsmash (this needed a buff? whatever I'll take it!), he was turning out to be a sweet char even before I knew about the QAC, which just gives him even more rape approach and combo potential. Wow, that was a long sentence... lol Anyway, I used to use pika for a low tier in melee, but never got particularly good with him. He's changed a lot since his melee form, though, and definitely for the better. I was a little disappointed on the nerfs to the up and forward smashes, but eh, you can't win them all. The usmash is still a good move, and so is the forward smash, it's just been given effectively less range, since the sweetspot is now right next to pika, rather than at the attack's farthest range.
As predicted, fox's new floatiness and his several changes have made it hard for me to play with him, but whatever. I mentioned lucas, but I'm not entirely sure if I'll even play him at all anymore. I still have a lot of chars to unlock (I've only got falco, marth, luigi, and ness, and have been playing wifi most of the time), so I may end up picking up a completely different second, or even changing my main later, although that's unlikely.
Oh, btw, not sure if you guys have seen this yet. I couldn't be bothered to read past the last few pages.
http://www.youtube.com/watch?v=KyhnF4jZa_Y
What appears to be the new form of L-canceling
http://smashboards.com/showthread.php?t=152305
The beginning of the thread has some misinformation in it, but it eventually gets to the point. Basically (if I understand correctly) it's just doing those moves
really early in the jump, so that they end before you hit the ground, even stuff that you wouldn't think was possible, like ganon's or pika's dair. This should open up all kinds of new combo options, as before everyone had been executing moves after the apex of their short hop, and only a few moves auto-cancel that way. Using this method to execute moves would also allow people to use the moves that auto-cancel when used after the apex even faster, since now they would be able to fast fall them and still get the auto-cancel. Should be interesting, at least.