Here are a couple of articles from Gateworld on the third Stargate series. The working title is Stargate: Universe and will include the 9th chevron. I'm hoping the series will either be like Sliders or Star Trek: Voyager. Since the 8th Chevron is needed to dial another galaxy I'm hoping the 9th Chevron is needed to dial various multiverses or a farout galaxy.

Third Series is Stargate Universe

Universe deals with ninth chevron