Jeff,
Size isn’t everything. The GTX 280 (1.4 billion transistors) is built on a 65nm architecture. The Penryn on 45nm. So, that picture doesn’t really say much. This blurb from AnandTech is more enlightening:
“Intel’s Montecito processor (their dual core Itanium 2) weighs in at over 1.7 billion transistors, but the vast majority of this is L3 cache (over 1.5 billion transistors for 24MB of on die memory). In contrast, the vast majority of the transistors on NVIDIA’s GT200 chip are used for compute power.”