Last weekend's release of the November issue of monthly shoujo manga magazine Aria featured a prologue of the Levi-centric Attack on Titan prequel Kuinaki Sentaku (A Choice With No Regrets) from Gan Sunaaku and Hikaru Suruga. The manga doesn't really get underway until the January 2014 issue, on sale November 28th, but the chapter did have a color title and opening page.
It's not a long chapter, only about a dozen pages. And, it's probably not too much of a spoiler to that Erwin shows up the end.
There are a couple of things that fans are making a big deal out of...
That wrap on Levi's arms is seen by some as a parallel to a non-animated Mikasa flash back:
There's also speculation tying those grates to geography relevant to material and manga and novels that haven't been released in North America.