Problem:
Revit Architecture 2010 crash at startup/splash screen, it just quit with no errors

Fix:

Delete the following file:
Windows 7
“C:\Users\%username%\AppData\Local\Autodesk\Revit\Autodesk Revit Structure 2010\ENU\Components\WebServices\WSCommCntrData.xml”

Windows xp
“C:\Documents and Settings\%username%\Local Settings\Application Data\Autodesk\Revit\Autodesk Revit Architecture 2010\ENU\Components\WebServices\WSCommCntrData.xml”