Personally, although Aruze/SNK claims to be continuing to support the Neo Geo MVS system, I have doubts about most of these possible future releases. I believe that a lot of the staff that worked on games in the classic series you mentioned, are gone from SNK. The only real possibility right now I see is Metal Slug 4. The MS series have proven to be very successful and very well suited for arcade games, and the SNK staff that developed this series may not have left the company.
Well, there's always NitD MVS, if nothing else . . .