You can change to the d-pad in the virtual keypad settings and keypad scheme. However it doesn't seem like you can have both the d-pad and joystick at this point in time so you still wouldn't be able to do finishers in the WWF games.
Tried a couple more games. Golden Eye is a little sluggish, it's also awkward to play since the control layouts have the Z button in the top left and its weird to shoot. Mario Party is laggy, IMO not playable. Mario Tennis has some graphics issues with the screen getting messed up from the special effects and also a little laggy. The Rush racing games work, 2049 doesn't seem to have sound, but 2 is playable. Mario 64 is a bit fast but it is playable. Tony Hawk is playable, even with the awesome soundtrack and all. Super Smash is playable, though the controls will take a while to get used to. Wave Race is playable but again fast. Battle Tanx won't load. Cruisin USA has some graphics error and doesn't display properly. Rampage 2 is a little too laggy for me to consider playable.
Overall, it seems the biggest problem are some games play too fast, kind of like a turbo mode. However, the thing is still in it's very first build so Yongzh has already mentioned in the description it has a long way to go, but it still plays many games in it's current state. Definately going to be awesome when it's tuned and running perfectly.