Shinji Hirako's Shikai: Next Month

It looks like the Fake Karakura Town Arc is yielding another surprise. Bleach episode 291 reads:

"Desperate Struggle with Aizen! Hirako, Shikai!"
"Aizen to no shitō! Hirako, shikai!" (藍染との死闘！平子、始解！)

It looks like we will finally get to see Hirako's shikai! What do we know about his nature from the Anime so far? For starters, a lot of the times he is seen upside down. Recall when he first confronts Ichigo by fighting in the sky during Isshin's surprise episode (Bleach episode 111). But then again, Shinji displayed another form of power later during the TBTP (Turning Back The Pendulum) Arc. Recall as Aizen was spying on Urahara and Hirako broke the ice by negating his hiding spot. The fact that it caught Aizen's surprise makes it an important ability. Does it mean that we can finally expect seeing a formidable threat go up against Sōsuke Aizen?

For those of you that keep up with the Manga, this is perhaps of little interest to you. But I'm sure seeing the animation won't be as bad as the latest filler that people have lately despised. Stayed tuned!