Just in from /Film [1]:

Late breaking news from the floor of WonderCon in San Francisco. The convention program features an interesting tease that features the classic Ghostbusters logo and “something exciting is coming to the neighborhood!” “Look for the big announcement at Comic Con San Diego 2008”.

Also:

Could it be the Ghostbusters 3 computer animated movie that has been in development for a few years now. Dan Aykroyd confirmed [2] the development of an animated Ghostbusters 3 in an interview last year.

Click here for the full /Film report! [3]