And of course a fully baked version whipped up by Fabolous has already been pulled out of the oven and wrapped in a .zip that anyone running a deodexed Froyo ROM can flash on their rooted HTC EVO via ClockworkMod Recovery (tutorial here). You can download it here but before you do, take note that this keyboard will replace the existing stock Android keyboard (not the HTC one) so you won't be able to switch between the two.
After you've flashed the Gingerbread keyboard, you may have to go to Menu -> Settings -> Language & keyboard -> Android keyboard -> Input languages to select English from the list. You can also just tap the settings button on the keyboard (between ?123 and the mic). And of course, to actually use the keyboard, long press a text field and tap Input Method -> Android keyboard from the menu that will appear.
It's always a good idea to do a Nandroid backup (tutorial here) before flashing anything since you never know what might happen. I flashed the new keyboard on my rooted EVO (SteelROM RevH) with no adverse effects, but your mileage may vary.[Droid Forums] Thanks, Man!