Being a Mac guy who works with After Effects, this news really bothers me. Keven Schmidt at Creative Mac benchmarked renders in After Effects CS4 on Mac OS X and Windows. The result? AE still renders faster in Windows, by roughly 1.2x. Now, AE has traditionally rendered faster in Windows, but now that we're on v9 and OS X has been around for 8 years, you'd think there would be significant improvements. Kevin about sums it up:
Either Adobe isn't tuning After Effects on the Mac at all, or tuning the buhjeezus out of the Windows versions. Hell, even single process rendering on Vista generally spanks multiple processes on Leopard, for the love of Pete.
This, coupled with the continued sub-par performance of Flash on the Mac really makes me doubt Adobe's commitment to the Mac platform. Are they still bitter about Final Cut Pro eating into Premiere sales back in 1998 & 1999?
As a side note, the other takeaway from the post is that enabling multiprocessing in AE doesn't save much time in either platform. For longer renders, it may help, but for those intermediate small batches, you may be better of sticking to single processes. This is something I've suspected for a long time, and I'm glad to see some numbers on this.