The way I see it, there are three possibilities for this announcement (two or more of these could be announced at once, keep in mind):
1) The TUF remaster details. This is most likely.
2) 2010 Tour Dates. It seems like this would be a bit early for the dates to come out, but we know they've been in negotiations for some time now, and that they probably would want the shows to be on sale for as long as possible in order to allow them to sell out. I'd say this is the second most likely scenario.
3) Release information for either NLOTH single four or Every Breaking Wave as SOA single one (see below).
4) Songs of Ascent. I'd call this scenario unlikely, but possible. U2 could have left Cardiff, gone on break, reviewed where they were on SOA, and decided right there that they had enough material for an album... maybe they could have gone into the studio during the break for a few days with Brian and Danny to finish things up, set it up thematically as an album, et cetera. Like I said, I doubt this happened, but it would certainly be
-worthy.