nope, as niphredil said, it's just Dr Thunderland Sr's yammering. The "Special Chapter" is chapter 11, that was published in Weekly Jump between the demise of Monthly Shonen Jump and the start of Jump Square. It has already been scanlated by one or two groups.
I hate to correct you but the special chapter comes in between chapter 10 and chapter 11 (in terms of publish date). Chapter 10 was in Monthly Shounen Jump. The special chapter ("Tegami Bachi to Dingo") was printed in WSJ (2007 #46). The actual chapter 11 was printed in the first issue of Jump SQ (2007 #12).
Check the RTS threads linked above.
The special chapter is in the volume 3 tankoubon, as mentioned. The Jump SQ chapters (chapter 11 onwards) will be printed in volume 4, releasing next month (5/2)!
Last edited by kirimi; April 19, 2008 at 12:07 PM.
An omake just means an extra. They tend to refer to extras included in tankoubon that are usually not story-related. For example, character interviews, sketches, 4-koma gags, etc. A gaiden would tend to refer to a side-story, usually a series of chapters that forms a stand-alone story directly related to a character or a portion of the original story. For example, the Kakashi gaiden in Naruto.
The special chapter is called exactly that, Special Chapter (特別編).
Last edited by kirimi; April 20, 2008 at 10:10 AM.