I feel like if ANY NA publisher can revive TO, it's Nexon. It's still going to be the premiere NA MMORPG publisher. If TO can't survive with Nexon, it can't survive. Think of all the MapleStory players out there, and the sheer volume of MS servers. Now think of Nexon having a 'Special Cash Package for Nexon Players to try this new MMORPG, Trickster!'
Every company is going to have it's shit. WoW's still regarded as THE MMO, and even their GMs use the infamous 'Working as Intended' line (which is 100% unrelated to James's post but I just wanted to point out that I think due to contracts it's all the GMs can tell us)
If Nexon doesn't pick it up I consider TO as good as dead. I don't think another gaming company could resurrect it, especially since 2d/2.5d is a dying breed. Sidescrollers will always have their place, but 3d games are more achievable as even standard systems are better equip to run them.