Finding Nemo was originally scheduled for Fall 2008 release. That date was rescinded and the new release date has not been announced.
http://bluray.highdefdigest.com/releasedates.html
tdb wrote:
2/19/09
Okay, Alien fans... you'll be pleased with this. You may have read at the excellent Bloody Disgusting website today that the first three films in the Alien series are rumored for release later this year on Blu-ray by 20th Century Fox. We've actually hinted previously here that you might see them on BD in 2009. Now, however, we CAN confirm that our industry sources have informed us that Fox's current plans call for not just the first three films, but the ENTIRE Alien Quadrilogy set to be ported over to Blu-ray Disc for a late 2009 release. This would include all four films in the series - the complete set will all extras - and likely new material created exclusively for the Blu-ray release as well. We understand that the work is still on-going and (as always with these Rumor Mill posts) all of this is subject to change. But with a little luck, the Quad set should make its debut in 1080p before the year is out.
Stay tuned!
http://www.thedigitalbits.com/rumormill.html#031209
I love both of these movies and can hardly wait for them to be released.