I don't know about dying as some games seem to potter on forever with far fewer subs than Rift, but I would say it is in serious decline. The world does not need another WoW clone (even a good, very polished one), I uninstalled is a few days ago because I found it lacking in a number of areas:
- The content with the exception of the two end game raids is too easy.
- There is a lack of distinction between classes.
- The classes/souls were all on the simpistic side.
- PvP lacks content, is grindy and lacks balance, both in terms of open PvP becuase of using the dumb two faction system, but also in Warfronts, they don't teh teams, so much of the time the outcome of the warfront is pretty much predetermned by one side outranking the other, which makes for boring PvP whichever side you are on.
I think the PvP side has declined much more than the PvE, I played the English speaking EU group and when I left they were pretty much down to one server (the other PvP server is dead).
SWTOR took a chunk out of the playerbase, some came back, but the truth is numbers were already declining, whilst I think the game will chug on with fewer subs, I do think there is a real possibility that GW2, Tera & Secret World could basically finsih off the PvP aspect of the game and GW2 especially may take a chunk out of th eplayerbase as a whole.