I'm sure it would be a corker. But I'm still waiting for Volume 2 of Chronicles - hurry up Dylan!

Not Pierce's biggest fan, but it could be an interesting read.
As for Dylan, the problem is that he usually doesn't remember many things (following his own advise, he's a man who really doesn't look back), and the people who are supposed to remember things for him keep dying away (like Paul Williams or Vic Maymudes). It's also possible that he forgot that he was planning on several volumes 
All true, stromberg! That said, I'm not sure if you have read Chronicles 1, but given its narrative structure whereby Dylan jumps backwards and forwards through time - often alighting on less key periods (presumably leaving the juicier or more interesting episodes/eras for the mooted later volumes) - I can only assume that a good amount of the material and notes required for the subsequent Chronicles must in large part have already been assembled in the process of researching, compiling and drafting Chronicles 1.
Anyhow, one hopes. He is getting pretty old though...