A couple of things to save some time:
1) The SP1 Update for Blend is for the Blend 2 product, not the June2008 preview. So you will either need to own a copy of blend, or download the free trial.
2) You cannot deploy RC0 applications to the web! Its a "preparation" release to ensure that your existing code will work when final release comes out.
3) RTFM first. There is a lot of information in the Word doc for breaking changes. Taking 30 minutes to read it thoroughly will save you lots of time and unneccesary forum posts!
[C# MVP]
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