Wow, I really wish this wasn't the day I bought a Vita and replaced my PS3, haha. I have the cheapie GT5 Logitech wheel ($100ish, I forget the name) but this thing would be a dream come true. I've wanted one of the insane ones for nearly every GT release, and the one I have now is the nicest one i've ever had even though its a cheap plastic setup.
Anyway, some day! For anyone who picked up GT5 today, you owe it to yourself to get at least a cheapie wheel as long as it can do complete turns. It is built for a wheel in every single way, unlike every other console "sim". As soon as you're comfortable turning all assists off, the wheel is the way to go for full control. It also actually has separate options for all popular wheel models, but i'm not sure if there are any left out. I know they patched in better G27 support after launch iirc so hopefully most are supported.