Shout Entertainment has a listing of several classic Nick shows they are releasing on DVD, unfortunately Seasons Two and Three have no release date as of yet.
Dunno if this is old or new news, but over at IMDB, I noticed that they have 4 seasons listed, with 2 episodes in Season Four. The Big Movie (Original Air Date 17 July 2008) and Phantom Fever (Original Air Date 28 Mar 2009), with no other information listed.
The Danny Phantom Wikia originally said under The Big Movie "Season 4 is going to be realested soon in late 2011 Summary TBA", but now reads 'Candidates for deletion / The series was cancelled sad to say in other words this cannot be here.'
'The Big Movie' and 'Phantom Fever' are not listed on Wikipedia's Episode List, but at the end of the DVD section it says "It's possible that new episodes may be made."
Anyone have any information on those titles? Thanks!