If I were building myself a new frame today - I'd do something pretty similar to this (note that I actually am loving my hardtail - another post about that another day).
Devin's frame has:
-100mm fork travel - sort of the standard these days. 80mm just feels like not enough to a lot of folks, myself included. Weird, since I used to ride 26" bikes with 63mm travel SIDs and thought they were awesome. Devin is actually going to use a Fox Talas that adjusts from 95-120mm - so pop the switch, and you change the bike from all-around XC to something a bit more aggro for the big descents.
-Tapered steerer capability. Necessary (Devin's not fat)? No, probably not. But it won't hurt anything, and on the plus side, it'll be wicked stiff.
-Direct mount derailleur. Super smooth shifts. I have actually moved away from doing these for super-short chainstay hardtails, because they've got a lot of dangly bits that get in the way of the tire (bummer) but this is an all-around XC setup with medium/long 44.5cm chainstays, so that's not an issue. And the shifting is excellent.
-Low disc mount dropouts. Easy to work with (win for me), cool to look at, and highly functional. Devin's not running a rack on this bike, but if he was, these would be the choice as well, because the caliper stays out of the way of the rack mounts. Note the downtube brake routing.
-S-bend stays, just to be cool.
New photo location - sort of a mug shot theme, I guess. The garage door is at least white so there's some contrast, but once again, my photography is awful.