You'll now be able to pay 160 more Microsoft points ($2) to get ten more Create-a-Class slots for emblems, films, and screenshots. "Flags of the World Calling Card Packs" are available for 80 points ($1) per regional pack.
Finally, "Personalization Packs" let you customize your weapon, Calling Card, and reticle for 160 points ($2), with One of Swords showing the "Bacon personalization pack" above as a very weird example. It's like a free-to-play model, except you also pay a bunch for the game! At least this stuff is optional, and isn't consumable.
"And yes," One of Swords writer Dan Amrich notes, "these will be coming to other platforms as well; when I know a date, I'll post about it."