I've heard there are a bunch of good changes for 1.0. Any ETA at this point?
Well, if you are speaking of 1.0 vs. 0.16, yes, some good stuff added
if you are speaking of 1.0 vs. last internal version taken from SVN, no, only small things will be added before 1.0 release.
I assume you would want to wait until after 3.13, but are we talking like days/weeks/months?
Not sure, but I think that being it released in a few days, it'll better to postpone the 1.0 to wait for it and fix any compatibility problem.
Things that may be interesting from the list of changes:
Added ability to override modular XML loading in mod ini file
Improved Espionage screen (by Almightix)
Added city zoom to event popup
Exposed CvCity::AI_AvoidGrowth() to Python
Added ability to save cities, improvements, and resources as nifs from in game
Added Solver's events
Different unit artstyles can have different buttons
New button art for event plot indicator