SBS is a great, stable product, so why go and throw in a bunch of broken software into the mix?  Untested - yes, Vista and Office 2007 are beta, so known to have bugs that have not be resolved in them.

OK, so the 1st rule is never run beta software in production, unless you are doing so for known explicit reasons.  Vlad has posted on this a few times already.

I also saw that the SBS team have made a couple of statements about Office and Vista and the bottom line is that there are some known issues and Microsoft is addressing them.  Also, looking on one of the forums, there are a few questions people are asking, so be warned.

If you don't use the connect computer wizard, then joining a Vista PC to a domain is doable.  You might have a few Group Policy problems, so I would check things like "My Documents" redirection and firewall settings.  You will also get a few UAC prompts, but as Susan suggests, lead UAC on for your testing - the prompts should get less once the PC is set up and the latest builds of Vista should stop the need for prompts as you logon.

any problems, let me know or report them as bugs

ttfn

David