>>How dead will New Orleans be on a Sunday (also Mother's Day!)???<<

Ummm, that would be when H*LL freezes over.

Aside from the aforementioned French Quarter, Magazine St. in the Garden District and in Uptown will be a beehive of activity; shops, restaurants, sidewalk cafes, etc. Also, Tipitina's on the corner of Tchoupitoulas and Napoleon has it's early evening Cajun music show.

>>our plan to do that is to approach the city by driving south over the Lake Pontchartrain Causeway (seems like that would provide a great view of the city coming in)<<

My preference would be to take I-10 from BR to NO and drive through some of the swamp and marsh areas. The view of the city from the Causeway is not really that spectacular, too far away, or maybe it's because I've seen it a million times.

>>....visit the city....<<

Are you implying that you will be visiting for only part of a day? You won't get to see much. Yikes!!!!!!

>>then exit via one of the two bridges over the eastern end of Lake Pontchartrain...either I-10 or US 11...any reason why one bridge is better/preferred over another?<<

Since it seems like time is of the essence, take I-10. There's not much that's interesting in Slidell, anyway.

>>we'd both be interested in taking a look at some areas that still show signs of being ravaged by Hurricane Katrina...is there any particular place along this drive that still has not really been rebuilt and is not too far off the route???<<

I-10 passes the Lower Ninth Ward and New Orleans East. N.O. East would probably have the easiest off/on exits.