I interrupted one or more processes with a power down to swap out a SIM card and subsequently corrupted a few things being my MfE account and the Calendar. The result was a crippling near 100% CPU and memory usage by as-daemon and the Calendar.

I hope this post will come up in a search and save the next person some time and perhaps an unnecessary reflash. This was compiled from Google TMO searches and my own experience.

I could only execute a few things before generating the error: Too Many Applications Running. Then a reboot was required.

To find out what is pinning the CPU open Terminal and enter:

as-daemon - I had to delete my MfE account to stop as-daemon. I did this from Menu - Settings - Mail for Exchange - Settings - Delete. It took several attempts and long lag times to eventually access the MfE settings. In this situation there's probably a better way to do this from Terminal.

To stop the Calendar from pinning the CPU:

Warning: This completely deletes all calendar entries.

I think I'm done with MfE so I can't comment on creating a new account and re-syncing the Calendar with recurring events.

Fortunately my MfE account and Calendar entries were not too important and my N900 is functioning properly again.