That looks like a very legit article aside from the ones AppleJon and Konviktion wrote. At the moment I am very happy with my phone as I have no major bugs, battery life is excellent and everything works like a charm, but like the others I am also anticipating the release of a new update! More bells and whistles to play with!
Ya know, i suspect that is how the old rumour of July 5th. Got started. Someone saw that iTunes would check for updates on July 5th and assumed that is when an update would come out.
As for that post on Howard Forums some of it seems like a no brainer and some seems kinda fantastic. Leopard is definitely the key though. It wasn't delayed just to push out iPhone. I expect some serious enterprise features, especially in the area of calendaring and contacts.