This is what I've noticed in the short time I've been checking out Disney-related web boards. Anyone can feel free to correct me if I'm wrong.
The discount resort rates tend to come out roughly every 3 months. They might include or deduct a few weeks if, in that three month frame, a holiday is coming or already occuring.
About 4 to 6 weeks before one set of discounts is about to end, the next set of discounts is announced. Since most of the discounted rates are scheduled to end in mid-April, the next set of discounted rates (if there are any-a small caveat) will be announced somewhere in the first half of March.
I've also noticed that 8-12 weeks before one set of discounts is about to end, a bunch of "rumors" get started that WDW is thinking about reducing or eliminating the amount of rooms available at discounted rates, especially for Annual Passholders. :lookaroun
Though I would never say that WDW will never do away with discounted rooms, it seems that most people just get nervous. WDW knows that one of the main reason people get annual passes is because of the discounted room rates, and I would dare say it's a main component of their business model. No matter how many of us profess a love for Disney, there would be a major trickle down effect if there were fewer or no discount rates. Many who would normally stay at a Deluxe resort trade down to a Mod, those who frequent Mod resorts would tirckle down to Value resorts (or start looking off site and be really ticked off about it). Value resort-goers would go off-site or perhaps not even be able to afford to go.
Never mind the fact that, as WDW keeps expanding the number of hotel rooms available to the public, they've gotta keep them filled, because empty rooms would be an even greater sign of failure than rooms filled with discounted rates. Because if you're not at the resort, you're not buying the expensive souveniers. You're not buying the expensive food. You're not buying expensive drinks at lounges. You're not buying the expensive clothes at the shops. If they have to break-even with hotel rooms to get us on property, where we'll be more susceptible to that lightheaded Disney Magicesque feeling, that's a more desirable scenario than sacrificing the deluxe resorts due to no discounts.
And if they ever did opt to do away with discounts, they'd bring 'em right the heck back after that scenario I just typed occurred. It'd be a hard lesson learned.
Remember the "Character Caravan?" A bus filled with Disney characters, sent to the hotels to play with your kids, was supposed to make up for WDW getting rid of the Extra Magic Hour in the mornings. Off-site hotels really benefitted from that blunder, and that's why we're no seeing all sorts of extra hours for Disney Resort patrons, morning AND night. I can't imagine WDW risking another blunder like that, with all the trouble Disney as a corporate entity is currently having.
Be patient, wait until mid-March before you start to panic if there are no discounted codes by then. The only drawback is if you're trying to plan a vacation, but you can still reserve a room with one day's deposit at the regular rack rate, with the provision that you're going to switch to a discounted code when they're available. And if there really are no codes, let Disney know how you feel by cancelling your vacation entirely. They'll feel the pinch and heed the call.