I’m out in New York at the moment with some press and finally got the answer on the word count question. I was lucky enough to get chatting with Jensen Harris today – he is da man – on the user interface design. The word count feature uses 100% idle cpu and it throttles so that nothing gets trapped behind it. Apparently there was a bug on mac a while back that some recall where a cpu hit occurred from a word count feature but this is not true of new one in 2007. In fact if you have a really huge doc, the feature shuts down to ensure there is no impact at all on performance. The page counter feature is in fact the one that takes a little CPU but not the word counter. Glad to finally get the answer to that one.
P.S. I have logged Chris Conway’s issue in the comments below as a bug.