If you wander over to this URL, you'll see Skype has a "what's next?" campaign running, with random outdoorsy videos playing underneath "I wish I could share moments like these." Is Skype launching a video-chat app soon? [Skype via @Skype]
Is already available in the N900 since start of the year, at least, no extra app needed to install, just the PR1.2 OS official update. And Google Chat video call too since around the same time.
Too bad the N900 front camera is not too great, so your side of the conversation could be a bit dark and grainy.