So...I doubt it will be standard, but expect/hope it will be a CTO option, and not too extravagantly butt-raping prices.
Right now, I'm good w/16GB RAM but could use faster than my SATA SSD, and could leverage the extra RAM > 16GB to run more VMs.
I intend to keep the next MBP for at least 3, more likely 4+ years. Consider phone storage and phone/tablet CPU speeds and onboard RAM and storage and their trend over the past 4 years, as well as the relatively software size and RAM requirements as we move into 4K video editing, larger and larger DSLR and camera sensors, etc...all of this can move the bar from 'more than or enough today' to 'wow, I need more RAM to get 'basic' things done' fairly quickly.
Like someone mentioned, Apple doesn't shy away from a nice customer butt-raping on RAM and SSD 'upgrade' pricing, so I'm expecting them to likely allow for 4x soldered modules onboard, reducing their cost to provide 16GB or 32GB while keeping those Apple profit margins up.
Honestly, I'm not sure what I'll be doing if they do not offer a 32GB RAM option, as we can pretty much say it's unlikely to be user-upgradeable.. I guess at that point I pass on the new model, upgrade my 2011MBP SSD to a 1TB Samsung, and wait to see what Kaby Lake models bring in a year or so.