I'm not sure what I would prefer at this time, but if you're going to reveal some meta info, we'll all need that before we start the first campaign of the 4th era so that we have an idea what kind of characters to create.
I agree with Windblade that a general summary of events based on our high level 3rd era characters is in order, although this can definitely be posted on the boards. We don't necessarily need to do it in game.
I suppose you just need to go with your gut on what story arc you feel most compelled to DM after we start back up. You'll have had a nice break from DM'ing between Whitesword and Zunder, so do what feels right when all the 3rd era dust settles.