[Haskell] Beautiful concurrency with a Christmas flaour

Dear Haskellers I've been writing a modest chapter for a book edited by Greg Wilson called "Beautiful code". In the end I decided to write about concurrency and transactional memory. If you'd like to have a look at my first draft, go here http://haskell.org/haskellwiki/Talk:SantaClausProblem I would welcome constructive suggestions for improvement. The book is aimed at a general audience of programmers, not Haskell geeks, so I have tried to explain everything necessary as I go along. So if you are not a Haskell expert, your input would be particularly valuable to me. Happy Christmas Simon