HardMac posted a collection of rumors they've received. They don't seem particularly confident about the information but do provide some believable tidbits:
- Snow Leopard will not be ready before September. Significant amounts of work left on QuickTime X, Open CL, and Grand Central
- New Xserve in June alongside a Mac Pro bump to 3.2GHz with Quadro FX 5800
- Notebooks to move to Nehalem in November
- Final Cut Studio 3, DVD Studio Pro, Shake, Logic updates.
The Mac Pro 3.2GHz speed boost is conceivable as Intel did officially release the Nehalem Xeon processors that run up to 3.2GHz. Apple currently only offers Mac Pros that run up to 2.93GHz.