let's face it it could be delayed for three reasons:
1> Fiscal/Financial restraints
2> Not ready in time
3> possibly becuase of European PSP release set back
1> if it's not released for financial reasons (i.e. they want the sales to come in for the last quater) then that's a bit sh*t but understandable. However with GTA:SA sales so high they should care less about it as their company must be making mega bucks - but that also could mean they would want to space it out a bit longer (i.e. not merge PC/Xbox sales with PSP) This ties in with point 3 as well. The game is being developed in the UK (leeds) so perhaps they want to keep it as a UK PSP release title (following their deals with sony and the PS2 (ok, could be unconnected)). doing something like this wouldn't surprise me much.
2> I am hoping it's not being released becuase of it not being ready. This would be great news as it would signify that it's less of a direct rip of GTA3 like many think it will be. I wouldn't be surprised if it had great multiplayer features which need more time perfecting. As they are releasing the PC/Xbox versions a few months before the PSP version it could just be that they are all working and sharing code that will go in both versions and they just needed the time with the PSP to sort out things like local and wide area play. They could be doing other things as well as multiplayer, the PSP architecture is probably quite different to PS2 so they may be having a hard time getting things to run well on it.
Or they could just be being mean