This is a helpful exercise and it's always nice to have more than one wording available that tries to bridge the inferential distance.
One thing you might want to take a second look at is the first place you use the metaphor of sliding the probability - most likely you are thinking of the diagrams later in the piece, and while by the time you get to them, they're helpful, I'm not sure the description initially given is sufficient to make it more obvious what's really going on. What am I supposed to think "slide" means at this point in the piece?
Common Sense Atheism has recently had a string of fantastic introductory LessWrong related material. First easing its audience into the singularity, then summarising the sequences, yesterday affirming that Death is a Problem to be Solved, and finally today by presenting An Intuitive Explanation of Eliezer Yudkowsky’s Intuitive Explanation of Bayes’ Theorem.
From the article:
It may be interesting if you want to do a review of Bayes' Theorem from a different perspective, or offer some introductory material for others. From a wider viewpoint, it's great to see a popular blog joining our cause for raising the sanity waterline.