In Chapter 309, Page 13, we see Sasuke attempting hand seals for a jutsu, only to be stopped by orochimaru on page fourteen. Looking at the frames of page 13, there are some hints as to what kind of jutsu this could be:
Bottom Right: Sasuke is holding his hands in a Tiger Seal. According to the early chapters of Naruto, Tiger Seals are used in Fire based techniques, which is why it can often be seen in Sasuke's Katon jutsus. This would go with the idea of Sasuke defeating Naruto's new wind jutsu with it's elemental weakness.
Left: Sasuke is holding his hand up in the air, as if preparing to generate something in his hand. It is from this position that orochimaru grabs his wrist in the next page. This seems to imply that it would be a technique that is held in the hand, similar to the Chidori, the only difference being that this is held in an upward position, rather than a downward one.
Any thoughts (hopefully serious ones) on this are welcome.