No one has mentioned that Melancon's district is almost certainly going away in 2012 and, thanks to Katrina, he'll be running against either a New Orleans Democrat or against Boustany in a district anchored in current LA-7.
If he isn't running for Senate, it's because he wants to run for Governor in 2011 or genuinely wants to spend more time with his family in a few years.
The Democratic controlled state Senate would almost certainly block any plan that eliminates LA-03.
It's Democratic in name only. Louisiana's legislature is effectively controlled by conservative Democrats and Republicans, I believe, and many of those Democrats plan to run for Congress in the future as Republicans if it would advance their careers. The legislature did nothing to help Dems in 2002 redistricting and I am presuming that they will pursue the path of least resistance.
Louisiana is losing a district. The 4th, 5th, and 7th are protected by geography and, in the case of the 7th, demographics. The 1st is probably protected as a concentration of Republican political power and a source of economic power. The 6th could be at risk, as I'll go through below, but has the advantage of a large population. The 2nd needs to gain a lot of population, and the 3rd also lost many residents from St. Bernard Parish and other nearby areas. I think a legislature without concern for incumbency but attuned to partisanship would get rid of the 3rd in a heartbeat.
The options are:
1) Create a Baton Rouge-to-New Orleans district with a bare minority-majority. That's all well and good, but it means that the 6th, 1st, and 3rd districts must compete for the remaining white voters in SE Louisiana. What will those districts look like? Is it conceivable they would abolish the 6th in this case? (Perhaps.)
2) Put New Orleans in the 3rd district. Can Melancon defeat a New Orleans Democrat? I don't think so.
3) Put New Orleans in the 1st district. Is this likely? Assuming the Obama Justice Dept. blesses it, why would the Republicans of suburban New Orleans want a block of Democratic voters in "their" district?