Meh. Not a fan of the tiered loot idea or the WoW system of making gear obsolete in 6 months. There are other effective incentives to keep players playing: quests to access to new areas, epic storyline, great community are just a few.
>Quests to access to new areas + epic storyline

That only works once. Actually such content is probably the worse for DEVs. It takes a lot of time to make and players only clear it once. (Or couple times more when helping.) But it's not like you will log on and say "How I feel like redoing the quest to get access to [area_name]".

>Great community

That's not "an effective incentive". Not like SE can create that or help that... You can make a good game and have a bad community around it :s

WoW lost 3 mil subs in the last 3 years over this system eventually creating a soul-less game that everyone behaves their worst in.
Extreme shortcut there. WoW is getting old, it's only natural for a game of this age to start seeing the subscriber curve going down. A single system isn't entirely responsible for the loss of 3 millions subscribers. It's way more complicated than that. I'm sure that even Blizzard doesn't have all necessary keys to explain this fall (no one does).