That Magic Lantern Firmware is quite interesting. So it all comes down to this. Either I get the Nikon D800 and no extra equipment, or I get the Mark II / 60D / 7D with extra equipment, and the Mark III is overpriced I am leaning towards either the Mark II, 60D, 7D. One of those three, as it would give me extra room to buy extra lenses and other equipment.
What I find ridiculous though, is how expensive Canon still is. Consider the Mark II with a lens is almost the same price as a D800... (EU). I'm getting my gear at the begining of June, so I hope to still see some more feedback and help on which equipment I should aim and prepare for.
Given your interests, you will need some money to buy more than the body.
Studio photography: minimum = flash + some kind of background. Better = some kind of monolight kit.
Video: tripod + decent ball head at around $300-500. Possibly some kind of lighting kit. Stabilization rigs, etc.
Good zooms: full frame 24-70 or 24-105. There are no good and cheap full frame zooms -- even the upcoming Tamron 24-70 is around $1000.
APS-C: You have some cheaper off brand options if you go with APS-C (e.g. Tamron 17-50 f/2.
. Otherwise Canon 17-55 or 15-85.
A decent prime or two: Some good budget primes are the Canon 50mm f/1.4 or 85mm f/1.8.
The better primes are about $1000 each and up (35mm f/1.4, 135mm f/2, Sigma or Canon 85mm)