The following was posted on April 23rd. See specifically step 2 below. It not only implies that you can upgrade from GP 10.0 to GP2013 on the SQL 2012 machine, but that you should.
Dynamics GP 10/SQL 2005/Windows 2003 to Dynamics GP 2013/SQL 2012/Windows 2012
1. The first step depends on the version of GP 10 you are on. If you are on 10.00.1779 you can upgrade directly to any build of GP 2013. However if you are on a build before 10.00.1779 you will need to upgrade to that build in order to upgrade to GP 2013. Click HERE to go to the GP 10.0 Download Page to grab the required patch. Please note that if you are on a build later than 10.00.1779 you will want to check your upgrade path on the Upgrade Hot Topic page
2. Before you actually upgrade to GP 2013 you will want to move your databases to your Windows 2012 machine that you will need to install SQL 2012 on. Refer to KB 878449 for move steps.
3. You then can upgrade to GP 2013 on your Windows 2012 machine
In response to a query I wrote on August 8th, a response with the following
community.dynamics.com/.../222333.aspx
GP 10 is not supported with SQL 2012. If you move your GP 10 database onto SQL 2012 and have to run GP Utilities for any reason you will receive a compatibility error. If you are going to do an upgrade to GP 2013 which it sounds like I would recommend you do the entire upgrade with the databases on SQL 2008 and then do the server move to SQL 2012 after you have reached your final version
I am hoping to get some more clarification . These two statements directly conflict with each other.
We want to jhave our system down for the minimum time during the upgrade, and would like to upgrade on a clean 2012/2012 server while leaving our production server alone.