While Apple's current generation iPhone 3GS and iPod touch G3 use ARM Cortex A8 CPUs and PowerVR SGX GPUs chips from Samsung, as part of their iPad announcement today, Apple also announced their own chip -- the Apple A4.
Custom chipsets have been on Apple's agenda since they bought PA Semi (Palo Alto Semiconductor) and Steve Jobs flat out said they'd be used in future Apple mobile devices. That future, it seems, starts now.
Battery life -- 10hrs for the iPad -- was stated as a prime reason for going with a custom chip. As is typical for Apple, they didn't give any details (and likely the reason they're making their own chips is so that they can keep those sorts of things secret from the competition), but since they're rumored to be a massive ARM licensee, and owns part of PowerVR maker Imagine, we're going to go out on a limb and guess those are still the CPU and GPU respectively.
How much RAM lurks inside the iPad, Apple also didn't say, and since we only found out the iPhone 3GS has 256MB was after the tear-downs, we'll likely have to wait on those for the iPad as well.
Of course, TiPb's mind immediately turns to the chances of having an Apple A4, or similar chip, in the 4th generation iPhone and iPod touch. Combine that with 512MB or more of RAM, a Cortex A9 multicore CPU, latest PowerVR SGX GPU, and little PA-Semi magic and... who knows how interesting 2010 will become!