That particular bit of the article doesn't particularly interest me (I'm not so dumb I can't setup mame). But the rest of it certainly does. On the fly rotation and on the fly screen toggling/rotation/ect sounds really cool.
Also as a programmer I am super excited about mame finally getting with the program and using a modern version of direct-x. I use dx8 all the time and let me tell you, it is a breeze to program for. You can do all kinds of nifty effects, everything is handled as a 3d object, and rendering text is quick and painless. Aaron is really good with the programming end of things, so he'll make a nice, sturdy base for us to all work off of. Since this core would be based on super old, tech us younger guys will find it easier to contribute in terms of tweaking video options and such.
Also, something I'm personally interested in is implementation of directinput force feedback. Before it would have meant combining elements of dx7 and 8 which understandably, the devs wouldn't like to do. But with dx8 running the video, the dx8 object is already there, a person could also tack on the direct input 8 object and be ready to build the framework. Dx8 force feedback is farily easy to do, it's dx7 that's hard.