As part of PAX, the Halo Fest is the console equivalent to QuakeCon or even portions of BlizzCon, given the series has garnered such a solid fanbase in its gaming tenure.
At this year's Fest, series claimers
, 343 Industries -- built specifically to take on the Halo universe post Bungie departure -- revealed the first details for Halo 4 (due 2012), which it turns out is actually only part one of a decade-long trilogy called the "Reclaimer Trilogy" that will see players heading to an all-new planet (the one at the end of the Halo 4 trailer, or seen at the end of Halo 3 when completed on Legendary) with a renewed focus on changing up the series' alien architecture.
has a lengthy run-down of the panel discussion that went on at Halo Fest, which details that Halo will actually explore more of Master Chief and will also still include Cortana and is also pretty much a direct follow-on from Halo 3. Check out the full Eurogamer run-down if you're a Halo fan, because it's pretty juicy in lore and series detail.