Flash and AIR updates, more PC than MacAs for what isn't in the Mac OS X version, we're primarily missing out on support for GPU acceleration, multi-touch, and gestures. Adobe's reasoning for only supporting GPU-based rendering on smartphones is that it "decreases performance [in some cases]" and "driver support varies wildly," even though Mac OS X has supported native GPU-compositing ever since it introduced Quartz Extreme in Mac OS X 10.2.
