Unfortunately I've seen nothing close to Pox. Battle for Wesnoth is the closest open source game I can think of. Have you checked that out?
Cool concept but that art is god awful. I could never play a game that looked that bad. Pox's art is one of the best things about the game and why it should not die, just be reincarnated as something better.
Conquest of champions and Duelyst are sorta within thawing distance. Actually Conquest was sorta Pox 2.0 until DoG swooped in to save the day.
about 20 players online. The concept was kinda meh... They have done some improvements since it launched, but they released to early as well (including a Steam launch) and now the game is a ghost town.... If there ever is a Pox 2, the biggest key is to release it when it is polished...ugliness runs off people... hence our current status.... We have a great game, a good concept and even originality, but lets be honest, its not the most attractive game in the world when the music won't even play through a full match and not even to mention the other stuff....I think a sequel could be great if done properly.
forget poxnora. that name is tarnished and cannot be rehabilitated. the only way forward is to take all of the existing game assets and repackage them into a new game. Something like Age of Wonders perhaps.