How much do you really love the Retina Display? I've used Retina MacBooks at school and with pixel doubling, I barely notice at all. Plus, when using as a desktop replacement, my keyboard/mouse and monitor take over the experience anyway.
The problem I have is that the SSD on the 13" Retina is way too small. It's 128GB that would fill up especially fast if you're using it for Virtual Machines and as a desktop replacement.
I say go with a fully specced Classic MacBook Pro. Buy the i7 version, a 16GB DDR3 kit from Newegg ($60) and a 256GB Vertex 4 OCZ SSD ($200 or so). With the remaining money left over from the 13" MBP purchase, pick up an iPad and you'll be REALLY set.
By the way, I have a MBP 13 and I love it. I love being able to upgrade the ram/hard drive and most of the components myself. The issue with the Retina 13" and 15" is that you cannot upgrade. What you get from the store is what you're stuck with.