There are very few 738s flying around with the new F seats. Until recently it was actually only 1; not sure if additional ones have made it through mods now.
All 43 of the "lite" refreshes (for the 738s that already had large TVs) have been completed and 9 "full" refreshes (for the 738s that had small TVs) are finished as well (we think...can't be 100% sure without actually stepping on the plane.) We're tracking them here:
Official Delta B737-700/800/900 Mods Thread