I'll just wait and see, but my prediction is that in the next few years, 29ers will be the way of 26ers and it will be 27.5 everywhere. (of course I could be wrong, we'll see).
What I have also noticed, and this is just my experience, but the peopel that seem to be hard core 29er peopekl around here are fairly new to mtbing (say 5 or so years), are VERY fit, have no comprehension of what a 26er HT is as they started on a FS bike and have discovered thsi HT thing in the form of a 29er, they can go just as fast as on their FS bike, but it is lighter and "rolls better" and they don't even need FS to tackle the trails, not understanding that they didn't need a FS bike in the first place to ride these trails they could have ridden on a rigid if they had taken the trouble to try.
Anyway, maybe thats not everyone, but it seems to be the way things go in these parts.