There was no word on a projected release date in the initial news flurry, but as Jakob pointed out in an email… the official Reaper of Souls page says “Coming in 2014.” Scroll down to the bottom and you see this:
One other unrelated point; we put the info into the mega D3:RoS post but I’ve seen a ton of questions about it since then, so obviously not everyone has noticed. The Loot 2.0 changes will be added to D3C, in a free patch. They’re not just for D3X (though presumably the level 70, new skills, new tiers of gear, etc, are RoS-only). A quote from a CM on the Polish Battle.net forum confirmed this:
Wuluxar: Changes to the game systems will come in a patch preceeding the release of the expansion – they will be available to all players, including the ones that don’t have the expansion (of course for free).
In related news, a brand new tweet from @Diablo says that other new stuff will go into D3C, pre-expansion:
If you haven’t already, you should watch Josh’s presentation from Gamescom explaining all about Loot 2.0: it’s 8 minutes of new info and you can see it embedded if you click through.