Looks I can stop reviewing the "upcoming" GSL maps and start summarizing the ones which are now official!
1. Crossfire SE
2. Tal'Darim Altar
4. Terminus RE
These new additions bring the map pool to this:
Crevass, Crossfire SE, Tal'Darim Altar, Terminus RE.
*They are still keeping some of Blizzard's ladder maps in the pool:
Lost Temple, Metalopolis, Scrap Station, Shakuras Plateau, Xel'Naga Caverns, *
(Note: You can play these new GSL maps "GSL" when you create a custom match online. Better get practicing, I would not be surprised if they added a couple of these to Blizzard's ladder.)