Preface to Agile 2nd edition book available?

So, is there a summary of the changes since the first edition? It
would be helpful to see just exactly what in Ruby on Rails has
changed before ordering the second edition of the book.

Could somebody briefly describe changes to Rails since the version
covered in the first edition of the book?

There is slight info on the announcement pages:

On 6/4/06, Robert N. [email protected] wrote: