I'm not going to buy it. Why? Price and practicality. I just found a US store selling the digi-back for $5,000; there wasn't any word of rebates though. Beyond price, I question the digi-back's practicality. Pulling something in and out of the camera gives the camera more chance to attract dust and grime. What if I'm running down a street and the digi-back just falls out?
If Leica had come out with a dedicated digital SLR, yeah, I'd buy the damn thing with a set of lenses. But this product, while great on the outside, just makes absolutely no sense to me as a working photojournalist. I'm sticking with Nikon for digital SLRs.