Disclaimer: The Apple Mac Mini is not officially supported by VMware.
Here is a quick screenshot of the networking details including the Thunderbolt ethernet adapter on my Apple Mac Mini 5,3 running ESXi 5.1 Update 1:
Apple Mac Mini 6,2 Users
If you have an Apple Mac Mini 6,2 the workarounds described in this article are still required as well as an additional issue regarding the on-board NIC for the Apple Mac Mini 6,2. The issue is that the on-board NIC is not recognized and claimed by the tg3 driver because there is not a PCI ID entry in the tg3 map file. Note, BCM57766 driver is supported, just that it was missing the mapping (I believe this was the case in 5.0 as well). Working with VMware engineering, I was able to obtain the SMC fix and along with the workarounds that I built earlier for ESXi 5.0 and I have created a custom ESXi 5.1 Update 1 ISO that includes all the fixes and you will be able to install it on your Apple Mac Mini 6,2 without any further modifications.
Note: From my understanding, some of these issues have been fixed but just did not make it in time for the Update 1 release. I'm hoping that we will be able to get most of these fixed in a future patch or update. This is actually pretty awesome, given that this is NOT SUPPORTED by VMware, but engineers are still willing to help the community out!
UPDATE: When trying to enable vSphere HA, the following error "Could not find a trusted signer" is thrown. To get around this problem, you will need to manually install the vSphere HA VIB and then reconfigure vSphere HA. The easiest method is to SCP the VIB from the VCSA and then using ESXCLI and the --no-sig-check flag to install the VIB.
Here are the commands to run:
scp /etc/vmware-vpx/docRoot/vSphere-HA-depot/vib20/vmware-fdm/VMware_bootbank_vmware-fdm_5.1.0-1064983.vib email@example.com:/tmp
esxcli software vib install -v /tmp/VMware_bootbank_vmware-fdm_5.1.0-1064983.vib --no-sig-check