In case you haven’t already seen it, Matt Cutts’ report on Google’s Bigdaddy updates is pretty good reading. Bigdaddy is a major infrastructure and indexing update for Google. Bigdaddy is intended to resolve a large number of indexing problems – ultimately improving the way Google handles canonicalization of URL (Uniform Resource Locator)’s, illicit redirects, and various indexing show-stoppers like Javascript and Flash.

This is not to say that your Javascript menus are immediately going to be indexed by Google, however. The new infrastructure will simply allow Google to develop more powerful indexing tools over time.

At any rate, Bigdaddy is a long term conversion, changing over a new data center approximately once every 10 days. It will probably mean a lot of changes in Google SERPs as sites move up and down in the new indexing process.

On that subject, the comments on his post make interesting reading, as well. In amongst the bad puns and other jokes on "Big Daddy", there’s a lot of complaining about the results of the new indexing.

People just need to realize that search engine changes take a long time to implement! As the billions of pages in the index are re-appraised some will rise and others will fall – if Bigdaddy causes your rank to fall, all you need to do is wait. Assuming you have a well optimized page using ethical strategies it will eventually come back up!