I manage a bunch of ESX and ESXi clusters. What the OP wants to do is... for lack of a better word, useless. If you have GPU cards in a server/workstation then you should just install LinuxCoin on that box and run your miners. Installing ESX/i doesn't give you any benefit, even if it were possible to get the drivers to work with the GPUs, because the whole point of ESX is to virtualize hardware. Since by definition you cannot virtualize GPU resources, and even then miners use 100% of the GPU resources anyway, there's NO REASON TO USE VIRTUALIZATION TO MINE.
Who cares about his reasons? Theres a 20 BTC bounty!