I passed the VMware VCP510 exam earlier this week, so am now waiting on VMware to confirm it [and send the Workstation 8 license !]. It was a tough exam, seemed to be a fair test of experience with the product and the time allocated was balanced to the questions quite well.
Many sites offer advice for revision (read the VCP510 blueprint !) and what I found most useful were various mock exams on other sites (including VMware’s own) and Forbes Guthries’ vSphere 5 Reference Card.