3.03 OE-C firmware. Everything about the PSP interface has been changed, from icons, to sounds, to the waves in the background. It may be a bit gaudy for my tastes, but it's impressive nonetheless. To download this homebrew-only conversion, head over to DCEmu. Warning: because crucial files are overwritten in the process, you have a chance of bricking your PSP. Use at your own risk!
Video of the XMB in action, provided after the cut.