What drive speed should I be looking at for a VMware Infrastructure 3
setup? The plan is that only the guest OS will reside on them. Data
will be stored on a SANS unit.

The applications will be Terminal Server, SQL Server, E-mail Server.
The terminal server will be running two custom programs that access SQL
Server, Microsoft Office 2007, IIS, NOD32, and probably WSUS. The SQL
Server will be SQL Server 2000. The E-mail will be Groupwise, Scalix,
or Zimbra.

Currently only 40 devices in the place. I don't see a lot of load on
any of these machines.