There are also some brand new Triple Packs being released, however they're all Series 2 Skylanders that have already been available in singles. One pack has Eruptor, Stealth Elf, and Terrafin. The other has Prism Break, Lightning Rod, and Drill Sergeant.
The last of the Legendary Skylanders, Legendary LightCore Chill, is also apparently scheduled soon for release at Toys R Us but as of yet has not been spotted.
And finally, as well as the release of Hot Dog in the Battle Pack, for a short time at GameStop you will be able to get the Sidekicks from Skylanders: Spyro's Adventure (that's Whisper Elf, Terrabite, Gill Runt, and Trigger Snappy), supposedly through a spend $30 promotion but people have reported being able to just buy them outright. Stocks may not last long either way.