Is there a point in doing this on the Vita over getting a cheap PSP? Aside from say, only wanting a single device?
In my opinion, PSP games don't look any better on Vita, in fact, I'd say they look worse (with bilinear on or off), so even if I wanted Final Fantasy VII: Crisis Core, or Kingdom Hearts: Birth By Sleep, I'd still be more inclined to take my PSP with me. As far as emulators (PlayStation 1 not included) and homebrew go, unless I've missed some big breakthrough recently, it was never really good, or at least, I never felt it was worth using. A lot of emulators would randomly crash, and a lot of the games were incredibly laggy, even after fiddling with settings. I simply never saw the value in it.
I'm interested in hearing why people want to do this, although it seems like they simply want to migrate their PSP collections to Vita and use a single device, which is great for them.
EDIT: After reading the last page, I guess it IS just people who want to migrate their collections. It's a shame about having to give up newer firmwares for it though.