To be honest, I'm actually surprised how much support the game has gotten to this point, considering there's really no way to generate money from the game once a player has already purchased the game.
Now, I definitely don't want to go back to having an Auction House -- especially a real-money one -- but when so many players are disappointed in the drought of content, I can't help but wonder...
Why don't you give us something to actually spend money on?
Obviously, we've got the Necromancer pack coming out soon. But, let's just be real here; not everyone wants to play a Necromancer, and unless I've missed something, I don't believe there's any new content coming for existing Classes to experience.
Now obviously, if the Necromancer pack is hugely successful, then maybe we'll get more content. But really, I feel like it's a flawed experiment. Normally, new Classes come alongside Expansions, because it ensures everyone gets new content, even if they stand by older Classes. While selling new Classes ala carte could be hugely successful, I worry that it won't have a big enough impact to put other content into development.
Diablo III is a surprisingly replayable game. I think Rifts, Greater Rifts, and Bounties have given the game a huge lifespan, as have Seasons. But we've been farming the same content for a long time now, and no matter how much fun the game is, players are getting burnt-out from the lack of content.
I'd like to propose giving players other things to spend money on, which would in turn fund more meaningful content development.
For example, Character-Skins. Maybe I want my Barbarian to look like an Orc, or my Crusader to don Tyrael's D2 Angelic Armor (via transmog; nothing that would impact gameplay). Maybe take a page from Heroes of the Storm, and have certain Skins change the appearance of certain abilities, your character's Portrait, or even their voice-work (I mean, besides story-related voice-work, which would be too much work).
Transmog items could also be a big hit. Gorehowl, Frostmourne, Warglaives of Azzinoth; things like that.
Or, how about something a little more ambitious...
Add a new type of Goblin to the game, one that can also be encountered in Rifts and Greater Rifts. Upon killing it, a portal appearance in Town, taking you and your party to an entirely new area.
It would be somewhat similar to The Vault, except you and your party would face a non-stopo barrage of increasingly difficult enemies (preferably faster and higher damage, not ridiculous health-pools). Here, you would have a greatly increased chance of dropping Legendaries, and maybe even some new Legendaries, but once a player dies, they're done.
Essentially, it would be a Survival mode where surviving is literally impossible, so you just have to try and kill as many as you can before dying.
Now, here's the thing... To actually use the portal, at least one player in your party would need to be "Attuned", which costs real money. Basically, you'd be selling access to a rare dungeon, but once you purchase the Attunement, you'd always be able to open it.
It would be entirely optional, as you could always hope someone in your party is Attuned, or if you play with a close-knit group of friends, a single Attunement could cover you. But, for those who like playing with random folks frequently, it would certainly be a worthwhile investment -- or constant temptation.
Point is, there are ways to make money with Diablo III, and I believe players would be more than happy to pay, as long as we continue seeing new content.
Otherwise, I don't know how excited I can get about the Necromancer, when I didn't like playing one in Diablo II, and it doesn't sound like there's any new content to experience either way.
Now, adding the Druid on the other hand...