You know that just enabling ECC firmware support and support for 64 GB (which is basically all these new Xeons are) is likely just a few feature tick-boxes intel need to enable right?
These CPUs may be called Xeon, but you're not going to be seeing other Xeon features like 20 cores and 20 MB of L2 cache here.
They will be largely the same as a mobile i7 with ECC support and a couple of minor feature cripple tweaks removed.
Intel has made low power Xeons for a few years now.
edit:
It would not surprise me in the slightest to see this Xeon as an option or maybe standard CPU in the 15" Macbook Pro. ECC is a "Pro" feature and for people who require ECC support, the current Macbook Pros (and any other portable) are immediately ruled out until now.
I don't think some people understand just how important ECC is for fields such as scientific research, etc. - even if the user doesn't need a million cores and terabytes of memory. Regular machine with no ECC = maybe your machine crashes, you get a wierd glitch in something, etc. Scientific research for example, a memory glitch can affect processing of experiment test results.
Yeah, but who's doing scientific research on a Mac mini or Macbook Pro? You want maximum power and/or maximum RAM. You aren't going to find 4+ slots for memory on a Mini or Macbook Pro anytime soon and you are going to be heat constrained on both platforms.
It isn't that people do not understand how necessary ECC memory is, it's that in a portable and/or Mini desktop, there are too many other constraints to be used in Scientific research. Great so you have ECC, but the whole thing throttles because of the heat generated or you have ECC memory, but you can't get one with more than 16GB of RAM (largest DD4 ECC SO-dimms are currently capped at 8GB) which throttles your work flow.
Just saying....