I have uninstalled all extensions and still the problem remains.
After upgrading to Mountain Lion last night, Safari will not launch on my MBP. It simply stops and is unable to load it's first page. I have not had this problem on my iMac, Safari works fine therre. I uninstalled all extensions and it still will not launch. The progress bar simply freezes - but I am able to quit, try and reload, etc. (all buttons work).