Going somewhat OT, the early federal counts against the suspect are listed here: http://www.talkingpointsmemo.com/documents/2011/01/indictment-of-jared-lee-loughner-for-murders-attempt-to-kill-rep-gabby-giffords.php?page=3

I was not previously aware that there are penalties for attempted assassination of a member of Congress ( http://codes.lp.findlaw.com/uscode/18/I/18/351 ), and for killing or attempted killing of an Officer and Employee of the United States. My first thought would have been there should be no difference from any other premeditated murder (or attempt). On reflection, it makes a certain sense that a legal system would take special pains to safeguard its own bastions; whether that is hubris is open to debate.

Do you know if these charges replace, or are in addition to, other charges that may be applicable to "regular" murder or attempted murder?

Would those other charges be federal, or state? IIRC some states have different penalties for murder than others ( e.g. the death penalty ).