I just passed IBM 486 OOAD with UML. It wasn't extremely difficult but I did dedicate a lot of time to studying. My resources were UML Distilled (2nd edition) by Martin Fowler and Kendall Scott. I also used Applying UML and Patterns (2nd Edition) by Craig Larman. I found both books to be very useful but I found Craig Larman's book the most useful for the exam. Martin Fowler's book is very nice to read and provides a lot of concepts to use when designing your own code but I found most of these concepts to be "personal preference" and are not official UML terms. All in all, both are excellent resources.
I am not sure if IBM will come out with a new version of the exam. It isn't like there is a new version of OOAD or UML in the works so I do not think they are going to be updating for a while. Then again, I am not really sure when the exam was last updated or how long IBM uses the same pool of questions before updating that pool. I might go and try doing some searches and let you know if I find anything. If anyone else finds anything, feel free to share with the rest of us!