As someone who has been around for a while and doesn't play as much as I used to, here's my input:
When I play I set goals for myself: max, comp then trim. The first two aren't that hard, and can be finished in a couple of weeks. When it comes to trimming, there's maybe another week of hard work and then it's a pet hunt from there on out. Which gets insanely tiring, especially the second time around.
I guess what I'm suggesting is to add more requirements and achievements, and not to make the end game (for someone like me, who sees trimmed comp as end game) simply a pet hunt. I understand it will eventually come down to that, though, being as it's currently the hardest requirement.
In addition to that I would have to say aim for feedback more often, this is a great start. Poll some ideas you have to the community (something the new community manager could be in charge of?) And host more interactive events!
Oh, another thing: base updates on the many, not the few. I know it's easy to think "well these three really good pvmers can do it with their eyes closed, everyone else needs to step up their game" but that will only disrupt the community more and make them lash out for not thinking of them as a whole. Updates should be what's best for everyone.
And another thing I have always found to be true: people are selling WAY more than people are buying. I think the reason for this is because there simply isn't enough gp (like, actual gold) coming into the game. An easy way to fix this would be to add coin drops to bosses. Nothing crazy obviously, but something small that adds up after a while. I think this is essential for the economy to get going again.
That's all I can think of currently, I'll edit this post when more comes to me.