Austin Homebrew has them (at an insane price). The big retailers like MoreBeer and Northern Brewer obviously contract even more hops than the smaller sites, but they don't release them the moment them get them and space them out throughout the year (I spoke with a representative at MoreBeer that explained this to me during a call in which I was accidentally shipped Chinook instead of Citra). Citra was actually available on MoreBeer practically all year for a few weeks at a time on and off despite the demand being relatively similar to right now.
My understanding however (via Farmhouse on this very site), is that the Citra harvest hadn't been completely processed yet and will still show up on Farmhouse and other sites, but not on any particular schedule. It does seem from my shopping trips that Citra is going to be less rare than Amarillo though (The company/farm that owns the Plant patent on Amarillo only allows them on 5 farms and a significant number of those were allegedly hit with flood damage (even though there was a massive drought this year). I picked up lots of 2012 Simcoe without issue, but 2012 Amarillo was tougher.)