I am trying to setup Exch 2010 CAS array for our new Exch 2010 installation. So when I issue the "Get-ClientAccessServer" from Exchange 2010's management shell, I see that it has the Exch 2007 CAS servers as well as the Exch 2010. If I issue the "New-ClientAccessArray" command won't it try to include the two Exch2007 CAS servers? I'm still learning powershell right now so I could be completely missing the command that lets me specify the exact servers to include. I have also read alot of how-tos on creating a CAS array for 2010 but non seem to address creating the array when the current 2007 servers are still running.

The Client Access Server Array is a 2010 thing, so Exchange 2007 CAS will not be listed as members. When you issue a Get-ClientAccessServer, that's a different command and simply lists all the client access servers - regardless of version. You dont have to specify or add any server when you create a CAS Array. Any Exchange 2010 CAS in the same AD site are automatically added to it.