If you NEED a Mac Pro now BUY ONE. Waiting means your only buying it because you can afford it and want the latest and greatest, not because it has a task to perform!
Don't have much to say about the rest of your post. People have their opinion and people that are sick of waiting might get frustrated, with only a few words from Apple's side saying wether it will or will not be updated in the near future would be enough.
however your comment above is plain dumb.
It's not about the the newest, latest and greatest.... it's about spending alot of money on a pro machine. Which is now outdated. Especially the gpu in that kind of machine is a joke. Anyway, if you spend that money now and in 2 weeks the update occurs, that's just stupid and you would kick yourself in the nuts.
Maybe it won't have amazing new technology but at least the GPU will be better, maybe more RAM or more HD space... it might cost a few $ more or less that all doesn't really matter...
You will pay more or less the same but it will be the most current build which will be worth it's money.
if you go to the store to buy a watermelon, and you have a choice of one that has been there for 5 days or the one that just comes in fresh... you'll pick the fresh one.
An exception maybe, for bigger companies with larger budgets it won't really matter and your theory is correct, but for smaller businesses, with no huge cashflow, they want the best buy that last a long time.