I think they've left enough enthusiastic hints/comments to feel comfortable that the AH/DT format is their choic going forward. My gut feel is they're done with the big boxes for a while but one can dream of that OT2. There are a few features that I'd miss badly if I ever switched back to an OT from DT - an improved OT with those features built in, a DT XL so to speak, wouldn't be a canabalising move in my opinion. It'd be like synth manufacturers releasing 8 or 16 voice versions.
Anyway, have said it before but the next non FX box will surely be an 8 voice synth in DT's format. Like Cuckoo says, essentially a MnM 2. I'd jump on that in a heartbeat!