Right here: http://community.brickpicker.com/topic/10400-assumed-date-codes-for-production-runs/page-27#entry347889
If I cared to speculate (and I do), I would predict 13-14 major sets are going away (or are already gone except for vapors): TH, GE. HH. SC, KJ, R2, HE, SOH, WVM, ToO, R5, EEE, AA, and maybe it is finally time for good old DS.
Ones that I don't think are going away (that others have speculated will) are: TB, PS, 4x4, T1
Just IMHO, YMMV, etc, etc.
P.S. - 60% of the time I think I'm 100% correct, or 100% of the time 60% correct, or I can't fool all of the people some of the time, or something like that.