VMTN

That is unfortunate. Everything reportedly works fine, except the 10Gbps NICs. If you have the board without the 10Gbps NICs, you're good - though nothing with a Broadwell-DE processor series in it is currently blessed by VMWare yet on their compatibility list, I'm fairly confident it will be. This thing is built for visualization, so it's just a matter of time, you'd think.

In the meantime, someone will most likely get the *nix driver into a vib, if unofficially, since there's mounting pressure to do so as people scramble to get these servers from the various vendors (currently Supermicro and ASRock (of all places) has one shipping, but more are coming from other vendors). The question is when, as you and Supermicro have said.

If people keep talking about the need for the 10Gbps NIC driver, maybe that'll motivate some movement on the issue from one source or another.

Nothing I'm aware of. There was talk in another thread on the same subject that ESXi 6.0b was released, but there was no update to the VIB for the ixgbe driver - it's still the 3.x version from several months ago. No 4.x version yet.

Good news today, found over at this closely related thread (also on VMware communities):

Re: When will Intel(R) Ethernet Connection X552/X557-AT 10GBASE-T be supported in vSphere 6?

I don't believe Supermicro ever claimed 5.5 compatibility, and I don't really know if 5.5 will ever be supported for this chipset, but it seems likely we'll know more soon. Meanwhile, the outlook for 6.x looking promising!