There has been little movement today in NAACP v. Barbour, et al, despite the rumors that a three judge panel has been named. (It hasn't. I believe that to be MSGOP misinformation designed to hold the GOP legislators in line as they head home over the weekend.) The only movement so far today is the response by the House Apportionment Committee to the Mississippi Republican Party's and Secretary of State Hosemann's opposition to their intervention.
(Intervention means a party that has not been named as a plaintiff or a defendant in a lawsuit gets to come in and participate as a party to the lawsuit.)
The Committee's response is short and sweet, basically saying that nothing prohibits them from intervening in the lawsuit, and that's evidenced by the Court allowing them to intervene 20 years ago.
On another note, it has been reported that Senate Democrats have already joined the lawsuit. That's a bit misleading, as they have only voted to hire counsel to do so. They haven't actually filed a Motion to Intervene yet, although they surely will soon.
Update - This afternoon Judge Carlton Reeves signed an order granting the appointment of a three judge panel. In the order, Judge Reeves notes that the NAACP had asked for the three judge panel, and that all parties were in agreement that one should be appointed. Now that the order has been signed, it's up to Chief Judge Edith Jones of the Fifth Circuit to name the other two judges. More on that here.