All we can do is look at history and buzz, but the buzz is very very strong that they will merge, and history says it's overwhelmingly likely the points will merge.
No one can possibly know if they will end up with Citi or Barclays, but I'd go for getting the cards. What do you really have to lose?
And what else can they do but merge the points? One things that is true is that I don't think points have ever been actually lost in a merger. Or even a bankruptcy. (Maybe I'm wrong, I don't know what happened to Eastern, Pan Am, et. al.)
Just get 'em and don't sweat over it.