Hardware keyboard, wanna use the Epic to play console games. Serial would be fine for RPGs but games like Super Mario Bros suck if you can only press one key at a time.
Hell... my G1 can detect multiple key presses at the same time. Which is really helpful since Menu-X, Menu-C, and Menu-V do Cut, Copy, Paste functions.
I can almost promise you that it'll be able to handle at least two keys simultaneously.