VS2008 Beta 2 has a "Go Live" license, which means you can use it in
production applications.  I don't have the exact details of this
license, but if I remember VS2005 and it's Go Live license correctly (I
might be confusing things here), it had some limitations - such as a
requirement to purchase/upgrade to the final RTM version when it comes
out (so no running beta built apps indefinitely) and, I think (certainly
I experienced this one when trying things out, but may not have been the
Go Live version) there wasn't a re-distributable of the runtime - so
VS2005 had to be installed on the machine which would run the app.

Looking at IIS 7's Go Live License:

"A Go Live license is a license to use a Beta release of a Microsoft
product in a live production environment, before the actual release of
the product. It is important to also note that the Go Live license
transfers from Microsoft to the licensee, liability for any
unanticipated consequences, financial or otherwise, directly or
indirectly caused by using the Beta technology before its official release."

and

"Like use rights for any Beta release, use rights for Windows Server
2008 Release Candidate 0 will expire well after the final release and
Beta testers will have ample time to migrate to a publicly available,
officially released, final version of the product. The IIS7 Go Live
License expires on 4/8/2008, the same day use rights for Windows Server
2008 Release Candidate 0 expire and the Beta product becomes deactivated
and unusable."

D