Lyle Denniston at SCOTUS Blog has update his earlier post with links to the briefs:
New claim of presidential power
Posted by Lyle Denniston at 06:05 PM
UPDATE 2: 6:05 PM: Texas's brief opposing Supreme Court review can now be found here. The post below now includes some discussion of the arguments Texas makes.
UPDATE: 2:45 PM: The Solicitor General's amicus brief discussed in this post can now be found here.