ET is 8 years old game. With Brink coming out there will be more less players. Everything born in world, as it's 'expiry' date. Nothing is immortal.

If you want to revive ET, the best thing you can do is promote ET outside ET. Many online gamers, don't know what is ET and on top it's even free. Why? They are all busy playing BC2, Black Ops, etc all new games. Before there where less console players and now a days many people play on console.

Many are waiting for BF3 and Brink. BF3 is the talk of the town in market. I personally play Black Ops a lot lately.

If you want to promote ET, I would suggest to post it on different forums where they have no idea about ET and invite them to play ET. This way it will bring more players to the game in itself.

But again all above is just my thinking.