Those who have problems with ReportCrash which uses the CPU over 100%, this means that you have a program installed that is not compatible with Mountain Lion. I had the same problem and my MacBook Pro is running at 90 degrees with report crash using my CPU at 130%.
What I did is I rooted what's causing the problem by looking at Application / Utilities / Console, and by looking what's written usually on the bottom of the page and see which program is causing the problem. Uninstall the program that is causing the problem and that should fix it.
The program that was causing mine was the Eset Cyber Security which is an anti-virus program but it's not compatible with Mountain Lion so I uninstalled it and my CPU fan went back to normal.
Hope this helps to some people.