I'm playing catch-up at the moment with the 2011/2012 sets, so I'm holding off on 2013 sets for now - but last night I picked up the AT-RT - what a great set.
I think if I see the Umbaran (sp?) canon set, I'll grab that too - all I see in my local stores is an empty shelf space.
The rest of the sets, so far at least, seem to be plentiful.