Red 5 announced their new game "Firefall" at PAX this year. Scott Youngblood aka "Cornboy" the lead designer of Tribes is on the team. Firefall features jetpacks and deployables which will attract any Tribes player to at least give it a try. Sorry, no skiing or anything like it has been shown in either of the vids you can watch here.
It's a Borerlands type game with a class system and upgrades. Only the coop mode has been unveiled so far but there will be PvP. You can definitely see the influence that the ex-WoW designer and Red 5 founder brought to it.
Be sure to follow it and try to get into the beta to voice your "Tribes" opinion.