I wouldn't either, Canon can't afford any problems, I'm sure if it's an issue with the sensor they'll be recalling and replacing. I have reasons for holding off but theye aren't related to the black dot problem. Apparently the 5D II doesn't perforn all that well as a sports photography platform, apparently the focus is a little on the slow side and of course the frame rate is down compared to the 2/3 sensor bodies.
Given Paul's statements on his comparisons between the old model 5D and the D700 it may be worth looking at
this review, the 5D, at least in that reviewer's opinion, is a much better performer than the D700.