I know why the new mac mini is delayed.
It's because Apple knows I'm waiting for it and they just want to piss me off. They are all watching in the back room as I struggle with my Mac Pro 1,1 wondering how long I can hold off.
Right there with you (except a 2,1 which is basically the same as 1,1). I just went through the trouble of replacing a failed logic board in my Mac Pro to keep it running while I wait. Probably going to upgrade to Mavericks soon and hope I don't have any serious issues (I currently run Mountain Lion, and the machine won't sleep properly, which I assume is because it's unsupported and hacked to run ML).