Apple's yearly developer conference should see iOS 8, OS X 10.10, and likely some hardware.
8-Core Mac Pro Details Emerging?
|Processor #||Clock (GHz)||Bus (MHz)||L2 Cache (MB)||Price (in 1,000 unit lots)|
In the likely event Apple choses to use Clovertown Xeon core as the next Mac Pro CPU, educated speculation would indicate that Apple would elect to only use the X5355 and E5345, as they are the only models that support a 1333 MHz front side bus, which is what current Mac Pros use. In such a scenario, Apple may elect to keep a Woodcrest configuration at the bottom end for customizability (currently, Apple offers 3 chip speeds in the Mac Pro).
Of interest, the Xeon 53xx series will be using Intel's LGA771 socket, which is the same socket that today's Xeon 51xx series (aka Woodcrest). Therefore current Mac Pro users may be able to upgrade to 8-core machines upon availability of the new chips (expected later this quarter to PC manufacturers according to Daily Tech).
Also mentioned in the article were Intel's Tulsa (Xeon MP) processor and Core-based Kentsfield, aka Core 2 Quadro. Currently, the Tulsa (Xeon MP 71xx series) is highly unlikely to be introduced into a Mac due to its basis on the power-hungry Netburst architecture. Kentsfield/Core 2 Quadro is also unlikely to see an inclusion in any current models.