I really really hope for a SL2 or something new in the EOS M-lineup in 2016. I could buy the SL1 right now, but it has the old sensor and I want something... "fresh and more up-to-date". I will switch from full frame to APS-C.
Initally I bought the 6D just for astro photography. For that, it's an awesome workhorse (and not only for that). It's one of the lighter and smaller FF DSLRs, but it's still too big and bulky for traveling. Well, maybe I will just keep my 6D for astrophotography (it takes a lot of planning), and for everything else I'll use something much smaller. The quality difference between APS-C and FF isn't that great at daytime. And quality is actually a rather low priority. It's more about aesthetics and the joy of photography.
I don't like carrying around big and heavy stuff anymore. This doesn't mean I have to cut down on image quality. I learned a lot about image stacking, and with it, I can have everything I want, even without tripod. It changed my mind. Doesn't matter what I want to capture; nightsky, landscape, flowing water, rivers, sundowns etc... as long as my subjects are static, not dynamic (which is mostly the case). Photoshop's auto-aligning and stacking modes are just so crazy good... Carrying around less stuff makes me much more happy.