Sorry I should have been more clear with that statement.
I have the new X9SCM-F SuperMicro motherboard and an old X7SBi both require the Intel e1000 drivers.
On the X9SCM-F with ESXi versions 5 and 5.1 only one of the two NIC's work, the custom driver is required for the additional NIC to function.
On the X7SBi with ESXi version 5.1 neither of the two NIC's work, the custom driver is required for any NIC to function.
Also I should mention I didn't write or have any involvement making the custom driver, I came across it looking for solutions to my first problem, and it appears to have saved me again.
I'm sure that VMWare will resolve these issues in the future, but I would expect two IT giants like VMWare and Intel should be able to come to the market with working systems off the shelf, it's a little disappointing.