Yes, believe it or not, the manga series "Aa! Megami-sama" aka "Ah! My Goddess" is celebrating it's 25th Anniversary later on this year. (August 25th, 2013)
By that time, the manga will be in it's 300th chapter!!
(it's published once a month)
There will be another OVA released this Spring [link]
More info here, courtesy of The Goddess Project: [link]
So what do you think that Fujishima-sensei has in store for us, the fans?
There have been numerous rumors around the internet for several years hinting at a 3rd Season. ("Fighting Wings" was the 20th Anniversary OVA's, and that was back in 2008) there were 2 more OVA's released in 2011: "Together Forever" and "Hunters + Hunters"
Whether these rumors are true or not, depends on Kadakowa Pictures, AIC, (Anime International Company) and Tokyo Broadcasting System (TBS), plus how how well the next two volumes sell along with the OVAs.