Videochatting has finally come to Adium-- kind of. They report on their blog that a company called MeBeam has been working on a cross-platform Flash solution, and they've hooked up Adium to use that service. On their site, MeBeam seems a little aloof about what Adium is (they haven't actually ever used it), but they seem excited to have Adium users flying through their servers.
To get it up and running, you'll need to download the plugin from Adium's Xtras site, and then of course have a camera (and they recommend a headset) ready to roll. Unfortunately, it seems all the plugin does is break open a link to MeBeam in your web browser, and connect the two users up, so it's definitely not a native solution. However, Adium's Eric Richie confirms in the comments that this is not meant to be an end solution-- it's simply a side project "in the meantime." Adium is still working on native video implementation, and so we can still expect to see native video chat sometime in the future.