The Apple Blog has some details on Skype for iPhone, including screenshots. Basically it looks a lot like the normal iPhone phone app, which is good. I'm interested to see how it works like in real life. I've had the Fring app which allows VOIP connection on the iPhone via Skype, but I honestly haven't ever actually called anyone on it :)
Update: It's here. Well, in the US app store anyway. Hope it comes to Canada soon.
Update2: Seems it might not. This CBC story has this:
Chaim Haas, a public relations representative acting on behalf of Skype, said the application is available in every country in which the iPhone is on sale and in which Apple has an iTunes Store — with the exception of Canada.