Vaughn Off Thor?

According to The Hollywood Reporter, that Matthew Vaughn is dropping off another Marvel property.

“Thor” will be released about six weeks after “Iron Man 2,” and Marvel is
waiting for a script polish from scribe Mark Protosevich (“I Am Legend”).
Matthew Vaughn no longer is attached to direct the project because his holding
deal expired December.

I was impressed with Vaughn’s directing in Stardust and he could’ve done a good job with Thor.
I’m a little concerned about Protostevich, cause of the under impressed, I Am Legend, then the news about Asgard having a major role started to peek my interest, but this is a Marvel project and it has to have some sort of tie in to the rest of the other films that Marvel has under it’s wing.