Frankly, if you did that, you were... getting ahead of yourself, to put it nicely (some would say "just stupid", but I understand getting excited about stuff).
Never, never, never buy anything counting on preview "possible" feature lists. Ever. Period. From anybody. Never. Never. Never.
Have I said that enough?
Anyway, I think the outrage over this issue is a bit bizarre. I mean, seriously. Running Time Machine backups, particularly the initial one, over your wireless connection will be stupid slow; it's a metric assload of data. If you're doing anything else at the time, you're going to be suffering with the latency to the point of madness. And if you're just going to let it run while you aren't using the machine, then why not just plug in the ethernet cable and leave it alone?
I just don't get it, frankly. It smacks of stupid, ill-considered knee-jerk whining.