You can do that in 4.1 as well :)
The only problem is that if you run HA/DRS then the USB doesnt follow the VM. So if it moves of the server, then the USB is lost….
I dont know if they fixed that issue in V.5
First, HA and DRS are -very- different, not sure they should be lumped together like this.
As far as HA goes, I don't think you -should- expect any software to carry a hardware connection to a device through a hardware failure like that. In an HA event the Host itself died (or rebooted) so the hardware host to your USB device is no longer functioning.
In 4.1 USB connectivity can be retained through a vMotion as long as the original host maintains connectivity and power and the VM Guests themselves remain powered on and not suspended.
A DRS event shouldn't break the connection, similar to a vMotion. I have not directly tested this, if you're seeing otherwise, that may be a good reason to call VMWare support to possibly troubleshoot something that could be a bigger problem. Otherwise, your DRS events should be triggered by performance issues, which I would presume other VMs should/would be moved first. If you have a bunch of USB connected VMs on one host that seem to be heavy, manually vMotion them to balance the load, if needed.
Unless you're using Distributed Power Management and it shuts off a host that your USB devices are connected to, then obviously, that'll break it.
Basically, I don't think the loss of USB connection through an HA event complaint is all that valid. You should not be -depending- on a directly attached USB device like that. HA is all about recovering from hardware failures, and if you're depending on certain hardware, you're breaking that hardware ambiguity. I know there's certain software that can require a USB "dongle" or key, but there are other USB over IP solutions that might work better in that situation. (For the most part, that's pretty much what ESXi is emulating, anyway.)