At MIX07 new stuff was announced, at TechEd 2007 in Orlando names of products have been announced.
According to Daryll Burling these names have nothing to do with the year, but more about the financial year these products will be released. As far as I'm know, the financial year of 2008 begins before the calendar year of 2008. Meaning VS2008 might be released in 2007, but SQL Server 2008 can't be released at the end of the year 2008. We'll see! :)