Intel’s Xeon E5 is already in the channel says Boston. According to Marco Arment, this seems like good news for those awaiting new Mac Pros (although I’m not sure Ivy Bridge fits into all of this):

Since the Mac Pro’s introduction in 2006, it has always followed the Xeon CPU roadmap. New Mac Pros are released when Intel releases new Xeon CPUs for them to use. That’s it. I’ve given away my secret on how to very accurately predict when the Mac Pro will be updated (and when it won’t be).

I’m not sure if this means that my 16 core nerd fantasy is going to come true, but there’s been so much talk about Mac Pros disappearing that I’d love to see anything at this point.