Just a few days ago there were hints that Dawnguard would not be coming to Playstation 3 or PC. Now it looks like we will soon be finding out what exactly is going on with the DLC, as Pete Hines made this statement on Twitter:
Nothing has been said/announced about it. We should have info later this week.
This looks promising for PC and Playstation 3 owners of Skyrim, but we will have to wait just a few more days to find out the latest news on Dawnguard. So keeping checking back for when we have the information.