Both SG-1 and Atlantis' TV and film runs were over before 12/31/09, but there have been novels released more recently. I'm pretty sure that the novels count as obscure, but I definitely could be wrong.
Re: Stargate Universe, I'd argue that it has a sprinkling of cameos from SG-1 and Atlantis characters, but its principle cast is entirely different.
Stargates SG-1 and Atlantis
Re: Stargate Universe, I'd argue that it has a sprinkling of cameos from SG-1 and Atlantis characters, but its principle cast is entirely different.