SP's are a necessity, but what I want to know is what have they done to improve IIS 7? Here's what the release notes for SP1 RC says:

IIS was included in some Windows Vista SKUs to enable web-based developers to write and test their applications. IIS in Windows Server 2008 is a significant server role which requires Internet-level scalability and performance requirements. The IIS7 components have gone through significant performance and reliability enhancements since Windows Vista originally shipped, in order to be a large-scale server component. These changes do not affect most Windows Vista users who do not even have the IIS7 components installed, however because Windows Vista and Windows Server are aligned, these changes are included in Windows Vista SP1.

You can find the "complete" change log here: http://technet2.microsoft.com/windowsvista/en/library/005f921e-f706-401e-abb5-eec42ea0a03e1033.mspx?mfr=true

So does this mean that there is a full UI and ftp support? The current IIS available in Vista is very limited by this. You can configure most of the stuff in config files (like I did with http redirect and logging bandwidth and referrers), but I would at least expect the features found in IIS 6 to be available from the UI in IIS 7. I've googled around to find some  more info, but nothing yet. I guess I'll have to install the RC to find out. Not sure if I want to risk it though...