SharePoint 2010 Capacity Guidelines updated for SP1

Major changes seem to be more qualification on IOPS for large content databases, plus some more detailed understanding of the real limits of DB sizes in particular scenarios. Of particular interest is the idea that individual DBs could be up to 4TB in size (though why you would plan for one 4TB database rather than a number of more manageable ones is a different question)

http://sharepoint.microsoft.com/blog/Pages/BlogPost.aspx?pID=988