Does anyone in marketing care what the User Agent says?
Change that and be done!
Change that and be done!
One possible solution is to identify as IE <= 7 to intranet sites (which can be designated via Group Policy) and IE >= 8 to non-intranet sites. Of course, this means admins have to properly define intranet/non-intranet, which means much rioting will ensue.
Poor IE team. You're getting screwed because management decided to rest on their laurels.
...There must be a good reason why this would never work, because I don't recall hearing it proposed before.