I think that the scene is not stagnant. Nile, Cryptopsy, Spawn Of Possession, Dying Fetus, Immolation, Gorguts, are all doing original, innovative things with their music nowadays. Of course there are countless blast beat goregrind bands that all sound the same, but that doesn't represent the whole genre of death metal.
i think that death metal has become stagnant as most newcomer bands dont have much originality in their music to keep it going and a good style takes a lot to be selected out from other death metal bands. most new death metal bands are terribly average but most of the originals and older stuff is noticed more nowadays. I think it depends on how hard one trys to become a fan of death metal and to make it heard that keeps it going as death metal rarely features on most commercial applications. It remains much more underground than the new scene which varys mainly toward punk and popularized music. I think that your peers and the option of filesharing makes one more informed into bands as they are able to get a taster of a band to see if it is likable and then if it is good enough to them to then go out and but the album. Your peers vastly effect what music you listen to i think as for instance if you grew up in a school where punk overpowered most genres, you would become more attentive to punk music than perhaps what you listened to before. Band such as slayer, nile, carcass, cannibal corpse etc will still be noticed.
true actually, well its pretty stagnant where i live in britan, despite you will still find many true metallers who are fans of death metal, maybe its more active in different areas.