There will be another GTA for the psp according to Take Two. No one knows when or what.
they never said there would be another GTA for the PSP, they just said look for more on the GTA franchise in 2006, it could mean anything from the PS3 to the PSP...or whatever else they may be thinking of doing. Its only a speculation that another GTA could be for the PSP. But i think there will be another GTA for the PSP if LCS is a big sucess for them.