Dota 2 datamining leads to EP3 weapons, a potential space game?

While the rest of the world waits for Dota 2's beta to fully open up, some folks lucky enough to already have a key have kept busy by datamining the beta's files in search of any new information. Along with tracking down evidence of a Dota 2 store front, there's also mention of the long awaited Half Life 2: Episode 3, and potentially mention of an all new Valve game involving space ships and nebula.