The new iPhone firmware 3.0 is rumored to have multi-core CPU support according to ZDNet.
Apparently a four-core iPhone CPU rumor is making its rounds at Macword Expo 2009.
A guess puts the new PowerVR SGX543 multi-core CPU in the reach of Apple and the next generation iPhone. MacRumors sees though a new version of the ARM Cortex A9 multi-core processor as the more likely candidate for the next iPhone.

A super powerful iPhone would make it even more a gaming device beating the PSP in terms of performance.
2009 could yet be another exciting year for the Apple iPhone with either a new more powerful iPhone or a new small iPhone hitting the market.