I disagree a bit with the notion of just buying now regardless of timing of future models. Unlike computers, the cycle between updates is 2-3 years and if it's a matter of a month or two to get the next generation, then I'd say for sure wait. However, to quell the need for a 'camera now' maybe just get an already depreciated 5D classic for under $1000 that you can resell for very minimal loss vs. say a 5D II which in real dollars has a lot more drop in it's future. The 5D will allow you to focus on EF lenses you want to invest in and allow you to get familiar with full frame DOF.
i think what people are saying, in many of the posts about the 5D III, is that there is no definite date as to when it will be released. everything is speculation for now.
so if someone were to wait a month or two because they think it will come out, and then hear another rumor that it's coming out in the next month or two, they wait again. after that, they hear yet another rumor that it's coming out in the next few months, etc.


just kidding
