Can I get some examples of how many indexed pages you guys have and what your PR is? I currently have 16,000 indexed pages and have gotten to PR4 in the first 6 months of opening my site. I believe I had about 11,000 of those when my site actually hit PR4 on the last update.
For one of my sites I have about 100k indexed pages but no PR. I didn't build my site till after the last update....
There is no relationship between the two. PR stands for PageRank, not SiteRank, and has nothing whatsoever to do with how many other pages you have on your site. The only way it would have any bearing whatsoever is if people were linking in to every page on your site. Only pages that have non-supplemental pages linking at them will count towards your overall PageRank. -Michael
If you have indexed pages that have PR and are actual backlinks then it affects PR, but otherwise no.