This is not yet a guess, just fun with numbers.

If Difficulty were to go up (just) 8.32% this go-round, we'd be at difficulty of 1E12.  I recall late summer 2013, when no one believed that difficulty would hit a Billion by the end of the year.  (It did, block 276192, on 12/21/13)

I've been sharpening my dart this week.  This is a more difficult prediction than I thought.  Thanks for funding the contest!