When will naruto shippuden 40 release?

Well it supposed to come out the 20th. 12/20/07 There actually going to show to episodes that night too.

260 Kyubi Unleashed!!:

Kabuto reveals that he is still loyal to Orochimaru as Orochimaru informs Yamato that he knows Naruto and the others are watching nearby. Angered by Orochimaru's talk of Sasuke, Naruto unlocks Kyubi's third tail and does battle with Orochimaru, but will even this be enough to defeat one of the Legendary Sannin?

and

261 Secret Mission Start:

Pushed even further by Orochimaru, Naruto undergoes a horrific transformation as the dreaded fourth tail forms. Passing through the bars and into Kyubi's clutches, Naruto becomes a miniature demon fox himself, unable to tell friend from foe. Luckily for everyone, Orochimaru is directly in his path. Meanwhile, Sai ditches Yamato and Sakura to do a mission of his own.

This thursday on japan and veoh will have it after 10 o clock

It's a one-hour-long episode that combines episode 40/41.
It airs in Japan on Dec. 20, so it'll be fansubbed and released here on Dec. 21. ;3

Well it supposed to come out the 20th. 12/20/07 , you will be able to watch it at http://animeland.co.nr/ , That website updates the fastest

It should come out Thursday night, and can range from like 8-midnight...go to http://www.watchanimenow.com
They are really fast with putting it up, and have really great quality of videos!!
And they come out usually every Thursday night, unless they take a break!

Here the info from http://www.narutoshippuden.info
"Next Naruto Shippuden episode 40-41 will be on Dec 20, 2007. This will be a special double episode. So come on watch it here next week."

You can watch or download it here:
http://www.narutoshippuden.info
http://www.naruto-anime.info