The confirmation has been nearing ever since the Avengers movie has been in the news and Edward Norton said he would not be part of the franchise. So it has been in speculation for some time now.
The Avengers panel was waiting for Comic Panel to announce the big news. So everything will be clear at the Comic Con Panel. It is almost certain now. News doing the rounds are the confirmation of Joss Whedon to helm the huge Avengers project.
Joss Whedon is known for his work on Buffy the Vampire Slayer, Angel, Firefly and Dollhouse. So you really cannot expect anything great from the guy. So it will be another box office hit in my view.
Another piece of news that has become quite old now: the presence of Jeremy Renner as Hawkeye. Hawkeye is an orphan with a talent for archery that after seeing Iron Man save the lives of some people at the carnival, decides to become a costumed crime fighter himself. He was mistaken as a criminal, however, and hunted down. Iron Man was the first person to allow him into the Avengers mansion. So it will be cool to get a confirmation on that as well.