I realize no one can give a definitive answer but is it reasonable to think the next release of ESRI JSAPI will be built on top of dojotookit 1.7? And will be released in the next 2-3 months? Any documention for preparing 1.6 code for the move to 1.7 that takes advantage of some of the loader features introduced in 1.6?
I work on the JS API team, and while I still can't provide a definitive answer for dojo 1.7.x support, it's probably not going to be in 2.8. We're still working with the dojo team to resolve some issues related to the new loader. This has taken longer than anyone expected but we will get there. Apologies for the delays.
I didn't program with ESRI JS API but I'm a usual Dojo programmer. Dojo 1.7 is almost backward compatible with 1.6 It has many improvements and bugfixes.
The most notable change is the way you create widget and also how do you import then with the "require" sentece. Anyway you can continue working like in a 1.6 way, it is not stricktly necessary to change the way to 1.7