I hope the WordPress plugin utilizes the schema you’ve developed. Due to the my site being pretty new I’d definately go by age, but for major sites with tons of traffic I think the comment weight is a great way to go!

My advice is to prioritize indexing based on a few parameters.
ie. for the drupal module i created, it does one of a number of things:

a) It changes the priority value based on time of posts. Newer posts have a higher priorty value, older posts have a lower value.

or

b) It calculates priority values based on number of page views *that day*. Pages that have alot a views in a single day, are likely to have more comments, or are going to be very valuable to get indexed.

or

c) It calculates priority values based on the number of comments. ie. the page with the most comments gets 1.0, with every other page with less comments getting a smaller value greater than zero.

These simple techniques allow you to ‘push’ up the pages which are likely to be the most value to be indexed.

cheers and great post!

jordan willms at stream of conscious
http://www.jordanwillms.com