Overall it's a fantastic and overpriced device, fast, amazing screen, great SSD.
At this stage I would wait for the 2013 update - most likely coming out some time in June.
It's not perfect - I hate that it is virtually impossible to upgrade, and the graphics capabilities are at the borderline of what is required to drive the retina screen - again, the 2013 update should be better. Some users report ghosting issues with their screens. Applecare is basically a requirement because if anything breaks and needs to be fixed, it will cost bazillions.
Biggest decision point is the form factor. Do you really need a 15"? Because if portability is important, get the 13" -the 15" is not very light. And of course, do you need the power? Because otherwise get the Air - it's far lighter and cheaper.