There has been a program that runs homebrew EBOOTs for some while, PSPE, though its functionality is a bit limited and from what I've heard.
Also, by what factor do you think ISO users outnumber developers, more specifically non-Lua PSP coders without a PSP sat in front of them? I'm thinking double digits, perhaps more.
That said, I'm looking forward to this program's development, be nice to run Me and my Katamari when someone's looted my PSP :]