Just to let you know where things are at with IIS 7 in terms of stability and reliablity, Microsoft.com has converted to their entire infrastructure to it. They are consitently in the top 5 of avaibility on the interent and if you talked to them like do, you'd know they take that very seriously.
Eric Woershing recently did an interview with Chad Kraykovic and Jeff Towes over at MS.com (as we call it internally), which you can find here http://blogs.iis.net/ewoersch/archive/2007/06/27/video-microsoft-com-operations-team-opens-up-on-deploying-iis7-early.aspx. This is a very good interview that details many tips for those migrating a web farm to IIS 7. I suggest checking it out. Eric also did a great summary. I liked this so much that I'm trying to get some labs and training created based on their best practices. That would be very useful as it goes beyond just IIS7. Things like "do this with your scripts", "use DSFR for content replication", and other tips that have been proven to be useful at Microsoft.com would work for most enterprises and hosters.
Excited about this new project!
-brett