I think we can all agree that the CE vs cr economy is completely broken. I just wanted to ponder on why for a bit, maybe brainstorm real solutions.

cr supply (decreases value)
-Clockworks loot.
:: The game primarily pays you in crowns, and by now players have figured out how to eke out the most crowns for their effort. Decreasing crown drops is only a stopgap measure, as players will just find the next-best way to get them.

cr demand (increases value)
-NPC merchants
:: Lets be honest here; no one uses the NPC merchants (other than recipes) so long as their prices are twice as high (or higher) than AH costs.
-House cut from AH purchases, Energy Market trades, and player messages
:: A pretty miniscule cr sink here, but I suspect raising this would just increase prices, which is the opposite of the effect we're looking for.
-Crafting
:: This isn't actually a cr sink, because the CE cost of crafting is so much higher than the cr cost.
-AH Featured Auctions
:: Here's a good one, but the high prices keep all but the rich out.
-Variant Forge
:: And here we get into the only good cr sink in the game, as it is the only thing that can be done with crowns that can't be done either with other players or with CE. We need more things like this, but I'll get into that later.

neutral
-Anything involving trading with other players
:: For the most part, the AH, the Energy Market, and direct trading are neutral because the don't actually add or subtract from the total amount of crowns or CE floating around the game.

CE supply (decreases value)
-Player purchases
:: While technically a problem, this isn't one that can be "fixed", since it's OOO's income. Sales and promotions are naught but a stopgap measure, since prices will stabilize right back to where they were once the promotion is done.

CE demand (increases value)
-Crafting
:: Gods, so much CE required for crafting. >.< As previously mentioned, the CE cost for crafting dwarfs the cr cost.
-Equipment unbinding
:: I don't think this is a major source of CE expenditures, but I could be wrong. The price is pretty high for the benefit, though.
-Supply Depot
:: Given how stupidly expensive equipment is here, I don't think this is a serious source of expenditures. But again, I could be totally wrong. I'm sure upgrades and keys get purchased on a regular basis, though.
-Elevators
:: While I'm sure most elevator costs are paid for with mist energy (or elevator passes), the fact that you ~can~ pay for elevators with CE means that, so long as the most useful thing to do with crowns is to buy more CE, the price of 100 CE (in crowns) will never be much lower than how much crowns can be earned by high-tier players in 10 levels. While I'm not saying it's a problem, I am saying it's a fact.

So, for crowns, supply is high and demand is low. For CE, supply is low and demand is high. Surprise surprise, CE is fuxing expensive and crowns are worthless. Economics 101 here. We keep seeing OOO trying to attack this from the supply end, either by nerfing crown drop rates or CE promotions. Neither have lasting impact. What is really needed is a permanent adjustment to the demand end, either increasing demand for cr or reducing it for CE. Personally, I'd rather see the former first. Which is to say...

Dear OOO, let us spend our crowns.
Let me elaborate. We need some kind of crown-sink(s) that is persistent, accessible, repeatable, and exclusive. The only thing currently that comes close is the Variant Force, and it kinda misses on the second criteria.
Persistent: It's always gotta be there. No one-shot event, we're talking a permanent feature added to Haven, the Guild Hall, or the Clockworks.
Accessible: It has to have a low barrier to entry. Read as: cheap enough for even newbies to use. If it's too expensive for people to use, then it's not doing its job. Scaling prices are your friend here. Giving the Variant Forge "Value Tickets" that are cheap, but limited to Low and Medium UVs would go a long way here, I think.
Repeatable: There has to be real incentive to do it more than once. The height and eyes thing was a cute idea, but the cosmetic things that you only have to buy once have no real impact on the market. And no, that's not me telling you to sell more cosmetic items that wear off after a month.
Exclusive: This is the important one. It has to be available only from the vendor (preferably not other players), and only with crowns (it doesn't drop in other forms).

So. Some permanent feature added to the game, potentially cheap enough for anyone to use (but with prices that scale up), can only be purchased with crowns (not found in the clockworks), with reason to pay for it more than once.
And to be entirely honest here, no, I don't have any ideas what it could be/do. I don't have ~all~ the answers. ^_^;