I have been wondering a bit about this myself. Strange that they can get AC just like that - I would think that key personnel at GW have a competition clause in their contracts...?
I have one in mine, and I am not even really in a position to reveal anything crucial about our business, not being a developer of the company software.
Then again, their minis are so much different from GW's that some of them would look rather odd beside their GW counterparts.
I think, much of the buzz derives from the fact that Mantic puts out their plastics at about half the price of the equivalent GW products. And with the current GW prices, there surely is a large market for such a thing.
Now, if they can make a set of rules that captures the feel of large battles, without putting in too many supered up characters and show-stopper spells, then I might even be tempted to try painting up a small army. I am rather sure, I have enough old GW plastics from various box sets to do so... if I can only find the time...