I was planning to wait the final release of the game to post a request but I couldn't watch the gameplay vids of the demo anymore without touching the thing! It looks gorgeous, it's fast like hell, and it's free-to-play.
What more can we ask for?
Tribes: Ascend is an upcoming free-to-play multiplayer-only first-person shooter part of the Tribes franchise. It is currently being developed by Hi-Rez Studios and was announced on March 11, 2011 at PAX East with an expected release in early 2012. It will be available as a digital download for Microsoft Windows, though Hi-Rez Studios haven't ruled out the possibility of an Xbox 360 or PlayStation 3 release in the future. Iconic aspects from previous Tribes games such as jetpacks and skiing will be featured in the game. Currently, the game is available to play in the form of an open beta. (wiki)
Garbage (not tested on mac tho)