Nope No need when you can get this:
Droid 2 Game Gripper
This way you have the best of both world a game pad and a keyboard.
The game gripper is awesome, but it doesn't have analog style controls or shoulder buttons. On top of that, its just one more thing to carry on you. I never use hardware keyboards, so no loss there.
Analog Controls? I wasnt aware of this. I thought this was a mouse like touch pad in the middle. I would prefer PSP style analog sticks myself.
Shoulder buttons? Again I wasnt aware of that. Guess I am behind the times on this phone, but really not sure they are needed for any of the current android games. With this being a playsation phone, they may be useful since I suspect it is going to have both the standard android games from the market, as well as PSP/PS2 and maybe PS1 ports avaliable from a sony market or soemthing. I dont think it could handle PS3 ports with out major compression to the games and some major hacking.
As for carrying the game gripper, I dont use it myself, as I dont game enough to waste money buying it, but really it cant be that bad. What else are you carrying that makes it such a burden?