Ok, so here's my take.
It's not always about what the latest and greatest gimmick is in my book. It's about what's available, what works, and what I can afford (both to purchase AND maintain). My bet is when the smoke clears and the ad men find something else to BS us about, that the trailing arm machines are going to be around for quite awhile. I've ridden both systems and agree with some others that properly set up, they both work. I won't be turning my back on them only because they aren't "cool" anymore.
The specialized machines we see and love to watch at the MX tracks are just that, specialized. They are not necessarily the best machine available for use on the mountains, lakes, or groomed trails, even though they are very obviously at home on the MX tracks, which is hardly how most of us run, or even intend to run. It seems like the last few years the latest and greatest has to be a twin, but it appears now that even though they have some good virtues, maybe they aren't the greatest thing available in real life, or at least there isn't as much difference as the ad men would like for us to have believed. A lot of guys that jumped on that band wagon are now missing their triples.
I guess my point is that I for one, am not going to believe that just because it won on an MX track last weekend, it will fulfill what I expect a machine to be or do. It's been a long time since I was on a track, and I don't think I'll be making a buying decision based on what the machine I'm considering will do there. I don't buy, drive, or pay exta for hype. I go with what I think will work, and then, only if it's at a price I can afford.