Pretty much since the New 52 started, we've seen a lot of "Where is ___?" over characters that have gone missing. One of those commonly asked is Wally West.
For many of today's readers, Wally was the Flash they grew up with since Barry Allen, the original (not counting Jay), died in 1985. It makes sense that with Barry back, having two Flashes in a new universe could be a bit much.
Dan DiDio, co-publisher of DC Comics, on Christmas Day, posted the following message on his Facebook page.
"Merry Christmas to Everyone! Even you Wally. maybe I'll see you in the New Year."
Now this could just be a tease. Dan could be joking. Or maybe with the mention of Garth in AQUAMAN #14, there could be something in the works.
It's likely nothing but we won't give up hope.