Yep, that's possible, just watch this video.
All this is again done by Dolphin emulator, which made Wii games playable in 720p! Games have various graphical glitches, but mostly it happens for game rendering special effects for 4:3 only. But at least it's possible to play games in widescreen mode!
You could post some of your comments here to ask a question, I'll be sure to answer them ^^
PS: for HD watch video on YouTube