This is a very interesting Discussion,
Although i am no Programmer, and certainly dont know the in's and outs of this hardware. I do know that in the PC world 2 processors are always better then one. Always.
If we were talking about 2 pentium 2s@ 200mhz each vs 1 Pentium 2@400Mhz And the operating system supported Dual CPUs, And the chipset was a fairly Decent one. There is no way in hell the Single P2@ 400mhz could outclass the Dual P2 Setup, NO WAY. ESPECIALLY if the dual setup had MORE Ram. There is no way in hell. I dont know about you guys but i am truly without doubt that the GP2X will walk all over the PSP in 2D performance. Unless.... Unless, the GP2X had a horrible Chipset Architecture, Unless somehow the people designing the chipset screwed up the data flow between Both CPUs AND Ram, this is a very big part of getting great Performance out of the Two CPUs. It is a BIG necessity that the ram be easily Managed between both CPUs, a great example of ram management in Dual Processor setups would be the Athlon X2 Series of Processors, these guys really knew what they were doing when designing this architecture. Although the AX2 line are in many ways 2 processors on one silicon wafer it IS a dual cored SINGLE processor. but its Dual Cores make it in MANY ways just like a Dual CPU Setup.
I think the GPX2 will be very satisfying for Develpers that know how to use both processors in sync. Hopefully the Ram and CPU managment is Decent so we can see pretty games.