this is the stupidest question i've ever seen asked next to "can N64 be emulated on the GP32"
If you have to ask this question then you've got some serious issues or you just know absolutely nothing about the 2 systems. But if not let me break it down.
PSP: large commercial support, UMD system w/memory card support that can go way beyond 128mb, 333mhz processor, 32mb ram, rapid growing community that within a few months already has emus that can compare with the gp32s that have taken years to develope and get good.
GP32: no commercial support, 128mb max SMC support "might change depending on the SD thing that someone is trying to make" overclocked 166mhz, few can go above 200mhz, 8mb ram.
If i had to guess, the PSP, emulation wise, will surpass everything the GP32 has ever done within the year. It already has NeoGeo CD emulator which GP32 will never have, and commercial support alone will make it "better" if you talk about units sold and selling points.