The only two things I really like about MMOs are new quests and fighting bosses. Quests require this whole persistent world, they're expensive. Screw that.
Let's make a game all about killing bosses. None of the fluff around it. You connect to the lobby. You pick your class, maybe tweak it a LITTLE. Not 12 items with gems and enchants, no way. More "blue Rohan" (fast hitter) or "red Rohan" (heavy hitter). Maybe 10 total skills, roughly half for core rotation the rest for utility.
Gear progression naturally works the wrong way. The game gets easier as you get better. Instead, kills on low difficulty modes should unlock higher difficulty modes. Alongside that, a ladder will control who you are grouped with to avoid that "waiting for everyone to get it" feeling. Since the game will have no persistent world, there's no need to shard the playerbase, keeping wait times low.
Let's make it free to play! Give away maybe 9 bosses in 3 arenas for free. Release a new paid DLC boss every... week? Is that really so much to ask? Offer a discount all-new-bosses sub and heavily discounted old boss bundles. Obviously it'll be easiest to find groups for the new bosses and all the buzz will be around the new bosses.
Let's make it fast! A raid boss is a natural 20 minute encounter. That's snacksize! You can do one before dinner without ruining your appetite (or being late to table). Let's put the tactics video right in the goddamn game, played by the devs, with their kill time for all the world to see. You can skip the video if you want to play blind or try to beat the devs if you're hardcore.
Ladder prizes... hmm... say, get to design a boss? :)
The impetus to writing this up was my survey submission to Trion after quitting Rift. I figured hey, even if they steal it without credit, I want to play it! But just in case I'll post the exact text I sent them here.
Make a PvE version of Bloodline Champions. With matchmaking by ladder.
Free to play, new bosses cost, old bosses available in packs.
Progression up difficulty settings, not gear.