I don't think the P5Q-E is out yet. Here's a review of it.
Here's a review of the Pro.
These seem to be the differences based on just looking and a quick skim of these 2 reviews. I believe both boards are very similar.
P5Q pro- 2- 16X PCIe slots, 3- 1X PCIe slots 2- PCI slots 8-SATA
P5Qe- 4- 16X PCIe slots(2 electrical?) 2-1XPCIe 6-SATA eSATA 2 ethernet ports.