After installing Office 2013 on your SharePoint 2010 box you experience the following, when trying to upload an InfoPath form:
There are some policy files that reference the wrong assemblies. The following post got me to the right solution: http://smindreau.wordpress.com/2012/12/04/office-preview-2013-breaks-your-sharepoint-2010-enterprise-notably-infopath/
Solution:
Basically you must:
1. Entering the path C:\Windows\Assembly\GAC_MSIL in the Start/Run
2. Delete the following three folders:
Policy.14.0.Microsoft.Office.InfoPath
Policy.14.0.Microsoft.Office.InfoPath.Client.Internal.Host
Policy.14.0.Microsoft.Office.InfoPath.FormControl
3. Run an IISRESET from a command prompt.
