The DotD remake DVD doesn't come out stateside until later this month, so I can't comment on teh quality of the extras.
I have heard that a remake of Romero's "The Crazies" is in the works. There is also a "sequel/prequel" to Day of the Dead called "Day of the Dead: Contagium" (probably straight to DVD release), but Romero is not associated with the project.
Romero HAS been greenlighted (finally) on his fourth zombie movie, however. "Land of the Living Dead" is in preproduction, with Greg Nicotero on board for special effects and with Tom Savini in the cast.
Here's a snippet from AICN:
"George Romero was on hand signing autographs, photo-ops, and offering some great Q and A. He said that he currently has three projects on his plate: Land of the Dead, Diamond Dead, and the Stephen King novel Tom Gordon. He says that Land of the Dead has financial backing and a script, so Land of the Dead will be the first picture he works on and I believe he said he will begin filming by the end of the year. He gave a brief synopsis of what the film will be about; it will take place farther along in the future from Day of the Dead, and it is set up as a city living in the now zombie-controlled world. The city will have a giant wall built around it to keep the undead masses out, and the problems and action will occur when the people of the city need to leave to get supplies such as food. The main overlying theme he wanted for this movie would be ignoring the problem, or rather how society ignores the problems around us until we are forced to actually face them. One other interesting note is that he finished the script to Land of the Dead, one week before 9/11, but no studio wanted anything to do with it, he has gone back and polished the script to better match the themes in today’s society than the pre-war society of 3 years ago."