This little mobo works well, when you boot from a USB Key. The Realtek NIC would not function, may be with an updated driver you could tweak it, but I used a Intel Pro 1000GT, but apart from that little niggle, your good to go. Going to use this as a Ultra Portable Server for a demo environment as this board will manage 8Gb RAM, so, if you want a portable server, you could do a lot worse.

I'm looking to buy this board for a mini low wattage ESXi v4 setup.
I'm wondering if you're using the on-board SATA ICH7.
thx

You are not able to enable VT with this motherboard. So you will only be able to run 32bit guests. The onboard ICH7 is AHCI so there is no RAID. IMHO It should not be on the whitebox HCL for ESXi 4 if it will not do 64bit guests.

When you say you will not be able to enable VT with this motherboard, do you mean it is a BIOS limitation?

I ask this because the motherboard does support Q9400S and higher CPUs that have both EMT and VT.

I myself was planning on the Intel DG45FC with a Q9400S CPU and uses a Intel® 82567LF for the NIC (which I hope will work out of the box).

I apologize I did what I hate others to do. I did not clarify. My research into ESXi 4.0 on a Mini-ITX board led me in to the Intel arena. Here are some links that may be helpful to others and will explain my post.

The links in this will lead you to Intel's site and specs.
Let's start with the
DG41MJ specs. Please note that this board has the G41 chipset. Which in the features section supports the Core 2/Core 2 Quad processors.

"Supports the Intel® Core™2 Duo and Intel® Core™2 Quad processors and Intel® Celeron® processor."

However if we look here at the DG45FC specs we see that is has the G45 chipset. So not only does the board support the CPUs but the chipset states that....

"Supports the Intel® Core™2 Duo and Intel® Core™2 Quad processors with Intel® Virtualization Technology,◊1 and Intel® Celeron® processor."

So without properly doing my homework I jumped in and bought the DG41MJ which itself does not support virtualization, so even with a 64bit VT capable CPU, only 32bit guest OS's are possible.

Also to clarify the G41 chipset does not have ANY support for RAID technologies even though it has multiple SATA ports. Even though the ICH7 controller is capable of RAID, it is not implemented in the G41 chipset.