The problem is not the leaking.... it is the fact that everyone expects all the rumoured to be launched at these events!
And when they are not launched, or at least announced, people get all frustrated.
And the reason people get so pissed is because apple lets so many months pass in-between updates. If they didn't let the systems get so out of date, people wouldn't be so hyped about updates.
If the Mac mini would have gotten the a 2.4 GHz Core 2 Duo, 2 GB 1066 MHz RAM, nVidia 9400 M, 250 GB HD... but same enclosure... do you think Phil (or Steve) should have talked about it?
No. It is isn't a machine to demonstrate. It is just an update...
And if that were the case they could have just put out a press release today and not mention it at the actual keynote. But instead they didn't update at all.
How many years has it been since a mini update? How many more months might it be?