For the second half of the series they've changed to the 2nd verse of the opening theme "Dress" (ドレス), however they are still just using clips from the first few episodes for the opening sequence itself. No matter how well chosen the clips are it still seems lazy to me and annoyed me about Stellvia (which also used clips from the first episode only). I hope the DVD version gets a revamped OP.
July 2005 Archives
Couldn't detect any changes in episodes 5, 7 and 8, but episode 6 has had a complete overhaul to some scenes. One odd thing I've noticed is that eyes have more detail in wide shots in the TV version.
Not like it's not been done before, but here's my screenshot selection of DVD improvements for Negima, mostly from episode 2.
While checking out the new improvements on the first DVD I spotted a new error that has somehow crept in:
|Negi's staff is no longer strapped to his back in this scene..|
..but it's back again in the next.