Did EA have anything to do with the shut down?
Nope. According to some recent interviews, Namco caused Hellgate more problems than EA did. But mostly, it was because an incomplete product was released, and before the game could be improved, the majority of the fanbase was too jaded to continue supporting the game, and with so much negative word out about the game, box sales died instantly w/ith no respawn.
As for Mythos, it never even made it to release, despite the very promising idea of the game and the payment model. However, within weeks of the closing, Max Schaefer (Executive Producer of Mythos, one of the former lead designers of the Diablo games) and Travis Baldree (Lead Designer of Fate and Mythos), as well as everyone else who worked at the Seattle office of Flagship started Runic Games.
Runic Games hasn't announced what they're making yet, but they've made it pretty apparent that they want to go for another Action/RPG-style game with MMO aspects. I'm very much looking forward to whatever they do, because I've never seen a more open, communicative development team than the one Travis Baldree headed up as Flagship Seattle.
I'm really looking forward to seeing what kind of art style they crank out now that they'll be starting from scratch...and REALLY looking forward to what kind of PvP system they unveil, given the fact that it won't be an afterthought this time. Mythos' Shadowlands and planned CTF matches were both afterthoughts, and the game wasn't at all built around them...so I'm really looking forward to seeing how Travis handles PvP in a game starting from the ground up.