Funny, I've also been contacted by an Apple technician recently, and he's sent me some information about what to do, to gather more info, should it happen again, which it "unfortunately" doesn't.
As stated above on May 10th, I've been running on 10.8.4 beta (12E55 by now) for a while now.
And guess what: I can really have my rMBP sit for 24+ hours, reopen, and it wont crash.
Whereas previously the screen would remain dark after opening the lid, it now turns on the backlight after about a second, and the resumeing goes on as expected.
My current pmset settings:
bash-3.2# pmset -g
Active Profiles:
Battery Power -1*
AC Power -1
Currently in use:
standbydelay 7200
standby 1
halfdim 1
hibernatefile /var/vm/sleepimage
darkwakes 0
gpuswitch 2
disksleep 10
sleep 30
autopoweroffdelay 14400
hibernatemode 3
autopoweroff 1
ttyskeepawake 1
displaysleep 10
acwake 0
lidwake 1
I hope they are pretty much default, because I reset them after fiddling around and ran my tests with them.
My bet: 10.8.4 fixes the issue, and I assume it has/had to do with the display or graphics-driver.