I can’t say that, as a user of the service, I feel confident this is a good thing for Typekit.
UPDATED (on Oct 3, 2011): Typekit now has a post up on their blog about it. The team is staying together (that’s good) and Typekit says that they will remain “a standalone product”, whatever that means (it doesn’t necessarily mean and independent company.
The good is that Typekit gets tons of cash, the bad is that it is coming from a company that makes seriously impressive products that have seriously confusing interfaces — also they make Flash. If Typekit can remain independent and just use the money as they want, this is nothing but a win. If.