This is the IX38 Max board, Max is the Abit high end enthusiast/overclocking line as opposed to the Fatality line aimed at gamers. Max has higher quality solid state caps, digital PWM, a status LED, and the necessary power and reset buttons on the PCB.

It also has 90 degree SATA ports, two eSATA and all the usual goodies. Pay particular attention to the PWMs above the socket, they are not all that common and are a really good thing. This is the high end board of the line, and obviously takes DDR3.
Let's say you don't want to spend $250/G for DDR3, where do you go? How about the Abit Quad GT, specifically the IX38 Quad GT? This one is very similar to the Max but has some not so obvious differences.
The layout is mostly the same, it uses the same higher quality caps and digital PWM, but this one uses DDR2 instead of DDR3. Most of the changes center around the memory, so that is where the details are different. Summary, Max = DDR3, Quad GT = DDR2.
Last but not least we have the AN78 which was not on display. This is the ATI 780 part from Abit, and it is fairly early. There are a bunch of 790 boards on the floor, but the 780s are all static where they exist.
Abit has working boards but it is so early in the process that they don't want to give out any secrets to competitors this far ahead of launch. Look for these boards on display in a few months. µ