The developers at Fring have updated their video calling application to support the Motorola Atrix and the Dell Streak. The application isn't yet available in the Market, but a quick trip over the the Fring blog (source link) will give you an email address to request the updated version before it gets uploaded to the Android Market.
This creates a sticky situation with the AT&T devices -- sideloading is blocked by default. There's no need to fret though, you can use the Sideload Wonder Machine to get past that one. You'll be chatting face-to-face with friends and family in no time. [Fring] Thanks, Jeremy!