Dont know if it works in 2.0 but were running Infrastructure 3.5 and recently purchased the USBAnywhere from Digi and it works like a charm. We use it on a VM that requires a USB dongle be attached at all times for a Bosch security program. Digi USBAnywhere for ESX
Hope it helps.
I assume they should work under Server 2.x. I have guests using Aladdin HASP USB keys running perfectly fine under both Workstation and Player.