The Wings of Valor were datamined and then confirmed by Josh a couple of days ago, and now the official info has been posted.
If you’ve already digitally pre-purchased the Reaper of Souls expansion, either as the standard edition or the Digital Deluxe Edition, then you’re all set! These bonus items will be granted to your Battle.net account as follows:
The Wings of Valor will be automatically sent to your existing and any newly created Diablo III characters via an in-game notification starting March 20, 2014.
If you pre-order Reaper of Souls at a retail store—either a physical standard edition or physical Collector’s Edition—be sure to redeem your Reaper of Souls game key via your Battle.net account on or before 11:59 PM PST on March 31, 2014. If you redeem your game key after that date, your pre-order loot will be consumed by the fires of the Burning Hells and lost forever. While you have six days from the time the expansion launches on March 25 to the time you must enter your code, to be safe, you should secure your preorder today and be ready to input your game key on launch day.
Interesting no WoW prizes for RoS pre-order, and instead moving on to the next and the new. I’ll echo the other comment/request I’ve heard; these wings should add to the Spectral
Ratdog Hound you get with the RoS:CE, since it remains tiny and needs all the help it can get.