twisters touching down in louisiana and mississippi. our rob marciano's following all that. we'll check in with him later. also, the tucson shooting suspect now officially an accused killer today. he's going to be arraigned on additional charges. altogether 49 charges related to that mass shooting that killed six people and wounding 13 others including gabrielle giffords. space shuttle "discovery" will return to earth for the very last time. if it lands today, it'll have spent a record 365 days in space, and there are only twoer more shuttle launches left for nasa. anybody out there who has flown on something other than the shuttle, you know, a plane, they always tell you turn off those electronic devices before you take off. don't necessarily get an explanation of why. what is the risks if you try to make one more quick cell phone call? send one more text message. there's a new report out there that takes a look at the issue of the electronics and the potential flight problems.