The NWO and Batista have been announced by WWE. The NWO names being inducted are the core group of Hulk Hogan, Scott Hall, Kevin Nash and Sean Waltman.
As noted last week, the other names not announced yet but confirmed are The Bella Twins, Jushin Thunder Liger and "British Bulldog" Davey Boy Smith.
John Bradshaw Layfield's name has been rumored (first reported by Wrestling Inc.) but Dave Meltzer noted that he has not been confirmed. An induction for JBL would make sense since Vince McMahon likes him and, aside from his in-ring career, he is the person responsible for the company starting the Tribue to the Troops shows.
Now that Davey Boy Smith is confirmed, it looks like Vader will not be going in this year. WWE only likes to induct one deceased wrestler (or team) so if Vader is going in then it won't be this year.
As you can see below, Mick Foley has been lobbying to get Vader into the Hall Of Fame. He did so last year and before his passing, Vader openly spoke about wanting a Hall Of Fame induction.