So I set out to fire up a fresh SP2010 install with the new BETA bits today...
Since I wanted to do a "Complete" install using SQL 2008 (not Express), I promptly referenced Neil Hodgkinson's "From the Field" blog top on "Single Server Complete Install of SharePoint 2010 using local accounts." Excellent post Neil! It was VERY helpful.
But being the control freak that I am, I wasn't content going back to the world of GUID laden Administration databases. So I did a little digging in the New-SPConfigurationDatabase powershell cmdlet and I found a handy extra parameter.
Instead of using just "New-SPConfigurationDatabase", try...