I gathered several estimates for the timing and extent of the next American Airlines devaluation from miles and points experts. I've averaged the guesses to produce a wisdom-of-the-crowd estimate that I hope is as close as possible to predicting the future as we can get.
Background
Last year, United gutted and bifurcated its award chart for Business and First Class redemptions. Now awards on partner airlines cost a lot more than they used to. For instance, one way in Partner First Class to the Middle East is 140,000 miles.

Delta released a few new award charts last year.

Through March 15, 2015, most transfers of hotel points to American Airlines miles earn a 25% bonus.

American has charged $25 per domestic ticket and $35 per international ticket to book award tickets by phone. That meant a lot of paying $35 for me, since only 9 of the 24 airlines you can book with American Airlines miles are bookable on aa.com.

American has charged $25 per domestic ticket and $35 per international ticket to book award tickets by phone. That meant a lot of paying $35 for me, since only 9 of the 24 airlines you can book with American Airlines miles are bookable on aa.com.

Update February 3: I first wrote about this deal on January 18. At that time, it lasted less than 48 hours. The space came back over the weekend, and I didn't write about because it disappeared in a few hours before I could.

It came back today, and it disappeared within 10 minutes of Gary Leff writing about it. Let's say it lasted one hour.

American Airlines and US Airways are both running sales on the purchase of their miles through March 3, 2015.

Now is a special time to earn American Airlines miles.

The personal American Airlines credit card is offering 50,000 bonus miles after spending $3,000 in the first three months.
The business American Airlines credit card is offering another 50,000 bonus miles after spending $3,000 in the first three months.

The personal deal has been the official offer since late October and the business deal since late November, so they've been around for three and two months respectively.

How much longer can we expect these amazing deals to last?

First, a quick word on why the deals

Now is a special time to earn American Airlines miles.

The personal American Airlines credit card is offering 50,000 bonus miles after spending $3,000 in the first three months.
The business American Airlines credit card is offering another 50,000 bonus miles after spending $3,000 in the first three months.

The personal deal has been the official offer since late October and the business deal since late November, so they've been around for three and two months respectively.

How much longer can we expect these amazing deals to last?

First, a quick word on why the deals

I booked myself a First Class award ticket from Cairo, Egypt to Washington DC with 15 hours on the brand new Etihad 787-9 Dreamliner for 90,000 American Airlines miles and a few dollars in taxes. Take a look at the suite:

https://www.youtube.com/watch?v=XlCS2ZZ7QVY
The Trip
I had already booked myself from the United States to Dubai to Bangkok on two flights in Emirates First Class on its A380. Read that Anatomy of an Award.

And from Bangkok to Luxor, Egypt in Business Class on a Qatar A380. Read that Anatomy of an Award.

Right now there is a ton of First Class award space available on American Airlines flights to Santiago, Chile for 2015.

I flew First Class on American Airlines to Buenos Aires two years ago. The flight and bed were comfortable, though the service was uninspired.