One of the microtransactions included in Patch 0.11.4 is a new helmet skin - Skull Hood (click for video). Like other helmet skins (for example, Demon King Horns), this one completely replaces what your helmet looks like and can have other microtransaction effects (like Divine Sign or Ice Crown) applied to it. This week is the last week of Path of Exile's third race season. Over 10,000 alternate art unique items have been given out so far, and almost 10,000 players have received the first prize tier. Over 5000 players have received the second prize. With 20 events left to go, there's still time to win one if you start now.
We're deep into the planning of Season Four and are putting a lot of thought into Five as well (as that one starts around the time we're patching in new content at release).