Thanks Ross! That is exactly what I was looking for. I'm still learning Powershell. I haven't had to do much scripting since the days when everyone used KiXtart. I was looking at the command references and, and had checked the Syntax page under the Exchange Management Shell Basics reference. It seems what I was looking for was under the Parameters page the whole time.
The RedistributeActiveDatabases.ps1 documentation page does not list -Confirm under the parameters section. If I had paid a little more attention to this page: http://technet.microsoft.com/en-us/library/bb124388.aspx I probably would have figured it out even without seeing it listed there.
Now I can see that the default is -Confirm:$true, so specifying -Confirm:$false will achieve the desired result.
Thanks again,
-Josh