There will always be rumors
This one might have a bit of weight behind it though. Mac Mini supplies are drying up and a school that placed a bulk order of Mac Minis had them pushed back from the 1st of June to the 14th of June. The 14th is a Monday though so we'll see in a couple of days if it pans out.
It doesn't suggest Pro updates though. The odd thing about the Pro update is that Intel's chips have been released. Apple wouldn't use the 8-core models as they cost too much. So the only possibilities are that Intel has a supply shortage, Apple is focusing too much on things beginning with the letter 'i' (maybe it should be called iPro to get updated quicker) or there is the switch to AMD going on.
I don't think the AMD switch is going to happen as it doesn't offer anything performance-wise but it allows some good options like having 4 processors in a machine. 12-cores per chip x 4 = 48 physical cores. It will cost in excess of $5000 but for people who need the ultimate personal workstation, it's a good option to have and costs the same as Intel's offering.
The 12-core 1.9GHz Opteron 6168 would be 20% slower than the highest end 12-core Opteron but costs nearly half the price. So 4 x AMD 6168 would be $2976 where as just 2 x Intel E7530 7500-series Xeon 1.86GHz would be $2782.
So the price doesn't go down but you can get more processing power for around the same price and it beats waiting on Larrabee. The power usage does go up a bit though at the high-end. The low-end could use the 8-core 2GHz 6128 Opteron. Again no price drop but 8-cores vs 4-cores.
Intel's 7500-series CPUs are fast processors but they don't have anything price-wise to match what is used now in the entry model. Apple use the 5500-series chips and they use the E5520 ($373), the X550 ($958) and the X5570 ($1386) - that's why jumping to the 2.93GHz costs $2600.
Likelihood is they'd use 32nm Westmere 5600-series but it would be:
E5620 2.4GHz - $387, 4-core 8-thread
X5650 2.66GHz - $996, 6-core 12-thread
X5670 2.93GHz - $1440, 6-core 12-thread
Entry model wouldn't be much faster than what we have now and all prices stay around the same. I feel that a 48 physical core 1.9GHz machine would be more interesting than a 12-core, 24-thread 2.93GHz machine. It depends on the actual performance of course and Intel could easily win in most real-world tests but physical cores are better than virtual cores and parallel is the way forward. They might get some discounts on good GPUs at least.
"Our Customers include BBC, ITV, GMTV, Tesco, Sony, Toshiba, 3D Labs, Creative Labs, Toyota, Walt Disney, Lockhead Martin, US Army, US Navy, US Air Force, British Ministry of Defence, plus many more."
Disney wants quad processor machines Steve, get on it.