I've got two Mac Pros. One for my home office, and one for my work office in downtown Everett.
My home machine is a MacPro2,1 from 2006. It has 8 cores at 3 GHZ, 8 GB of ram, an upgraded graphics card, and a couple of SSDs as well as some big disks in it. It has worked very very well for me over the years. I've been waiting to upgrade it, but Apple just doesn't want to release any new Mac Pros anytime soon and it has always seemed that new ones were just around the corner. So I've held off.
Like many folks, I've also just picked up a Retina MacBook Pro. I got the lower end model with 16 GB of ram in it. I didn't expect to use it very much except for on the road and compatibility testing. But I installed Xcode and built my projects on it, and I've just been blown away by the speed. Acorn compiles about 3 times faster on the RMBP than on my trusty Mac Pro.
This shouldn't come as a big surprise- it does have a super fast SSD and a 6 Gigabit data bus in it. It screams! But I really wasn't expecting it to blow away my Mac Pro in the way it does. I did get the lower end model after all (2.3 GHz Core i7).
So I've plugged in an external monitor to it, hooked it up to my home network via ethernet, and have been using it full time when working from home.
This is also the first time in around 10 years I've not copied over my home directory to a new machine. I've always had my home directory stored on a separate disk from the OS, so I could screw around with that stuff as I please and not mess up my personal data. I tried partitioning things the way I like it, but File Vault seemed to have issues with this. I never did figure out what that was about.
At any rate, that's where I'm at these days. And I figure since I waited long enough, this was bound to happen. I now have a new Mac Pro, which just happens to be in a RMBP body.