Toys R Us will have an exclusive Black Series 6-inch set of Star Wars Droids during San Diego Comic-Con, but will not be at Comic-Con.  As I work for Entertainment Earth and will be working on the booth for the show, I reached out to me for confirmation - and I can confirm this item will be sold online.  (I also assume at stores later.)  The droids are identified as R2-A3, R5-K6, and R2-F2 on the packaging.

Entertainment Earth Booth #2343 will be selling a number of other items for Toys R Us as well as their own exclusives, including some other Star Wars and Hasbro items. Click here to see the droid item at Toys R Us' web site.