I'll be buying the new edition. My group has been playing with the beta for the past several months, and we're enjoying it immensely. I don't think we'll be moving to the Askellon (new) Sector until we start a new campaign, but I can certainly borrow bits of new fluff and incorporate it into Calixis Sector adventures.
I'm getting it. No idea if I will be using it. Depends if I can find a way to change the characters from 1st Ed to 2nd Ed without too much hassle.
Switching characters from 1st to 2nd edition will require some work, but it certainly won't be impossible. Some skills have been consolidated together and many talents introduced in DH 1 expansion books aren't included, but it's still a 40k RPG. The character creation options are flexible enough that you should be able to represent just about any 1st edition character in 2nd edition.
If your players took a lot of advances from expansion books, things will be a little more difficult. Many of the more exotic options from expansions aren't included in the core game for space reasons, so you may have to recreate such characters from scratch.
Psykers are very different in the new edition of DH though. If a player has a psyker character, it's best to just recreate that character from scratch.
Will be redone the Sisters of Battle in the new edition?
There is no specific Sororitas class, but you can combine the Ministorum background and the Warrior role to represent a Battle Sister. They won't start with a bolter and power armor (a good thing, IMO) and there are no Faith talents in the new edition, but there's nothing stopping you from making a Sororitas character.
Do not ask why you serve. Only ask how.
Synonymous names include: Buried in Ferrets, Enveloped by Ermine.
Currently GMing a Dark Heresy 2.0 game and inflicting untold misery upon Martin Lockheed and company.