Sounds about right and sadly I don't think it will garner any support on a rumors site. Just look at the mac pro. There's a whole lot of commotion about getting an update in June, but the entire gainstown thread is populated by enthusiasts... and enthusiasts don't translate into sales for apple (just look at the specs of gaming enthusiasts rigs on their forums).
I think apple knows when to push people for more money, in my opinion the mini and iMac's next update will be the new mobile quad processors.... the next mac pro update will be later this year (towards christmas).
I'd love to see it earlier, I just think that no one (or at least the volume of people needed to make it profitable) is really chomping at the bits to get a performance boost right now. Quite honestly (when it comes to the mac pro), dual quad 2.8's should be enough for most power users for at least another year or so. And no target iMac or Mac Mini users (think your mom) are really throwing a fit because their computers are behind the curve. I know at work (database modeling, administration) I make due with a single quad (2.4 I think?) now