is there will be a wii version?

[TkSilver]

Well like the front page says
"Free & Open Source

PPSSPP is an open source project, licensed under the GPL 2.0 (or later). Anyone is welcome to contribute improvements to the code. Partly thanks to such contributions, PPSSPP's compatibility is steadily increasing, letting us all play our PSP games on the devices of our choice."

So if you want to try it all you need to do is find someone with the skills and the intrest to attempt porting it. As far as Currently updated platforms the only ones that seem to be updated are
Android
Windows
MacOS
Linux
IOS