Now that cataclysm talent trees have been released I can safely say I'd go with something like this:
http://cata.wowhead.com/talent#j0EMuegRIubIsco0xZMxcz but only given that glyph of disease keeps its current functionality.
Btw Rune tap and its improved form become near mandatory due to the new function of Will of Necropolis. Not only does it reduce damage you take by 25% for 8 seconds but it also refreshes your cd on rune tap and generates a blood rune so you can use it
Also using power auras you could easily create an aura to track this proc for easy reference (So you won't be like: OMG free blood rune ! 1!! ! 1 1 !!). Also unholy frenzy for the raid utility.
As for rotation: I'd open with outbreak and then hit blood boil to activate hemorrhagic fever, hit heart strike to spend the 2nd blood rune(or icy touch for snap threat since in cata IT keeps its increased aggro generation) and then 2x death strike or 1 DS and a plague strike if ye used IT. From that point on we use DS and HS depending on which runes are available. Also BB every 30 seconds to reactivate hemorrhagic fever and pestilence (with glyph of disease) every 45 seconds (with 5/5 epidemic) to renew diseases.
