Yes, there's a (slight) edu. discount on OS X.
When it comes to choosing when to buy, this opening to a Charles Moore opinion piece offers some sound advice:
I would say that no one (outside Apple) knows when the new machines will be out and what they will be like - all people can offer is educated guesses... and in some case, uneducated ones
Yeah, I'd read that somewhere before, but I didn't know who said it. And I tell that to lots of other people when they're buying computers...but its a lot easier to say it than to do it, at least for me. I have a bad case of perfectionism, in case none of you picked up on that...
So...anyone from Apple here..? PM me if you are... =P