Here is the situation I'm planning an upgrade from MOSS 2007 to MOSS 2010. My goal is to provision the minimum amount of new hardware. My Thought was to just setup new WFE's and re-use the existing SQL server (and same instance if possible) which is version 2008 (64-bit not R2). The rub is that I need to ensure the existing MOSS 2007 continues to operate while the new 2010 environment uses the same SQL server. The only snag I foresee is a potential conflict with default config database name (e.g. SharePoint_Config) while setting up new farm.
My Question is: are there any showstopper issues with two different MOSS environments using the same database server in this way? I'd also be interesting in any references that show this is a supported scenario with MOSS.