From what I can tell, you can only use valor to buy ilevel 496 armor in 5.2. Since we can't upgrade our stuff anymore, is valor of any use to someone with ilevel 496 stuff or higher?
Valor stuff from the new faction, at least. I'm not sure what else. For those that didn't gear up right away and still have to gear it'll be useful in purchasing 476 - 496 gear to boost you to 480 for the new LFR (or raid, if you're not an LFR'er).