I was reading a blog post today from a respected SEO blogger who was discussing something similar to get pages out of the supplemental index.
I found one of the reader comments on this blog post interesting:
In the context of trying to flow PR to your true content pages in an effort to help to get them out of the supplemental index, and not to waste PR on the way to your real content pages; it was suggested (unlike the “nofollow” link tag mentioned in the posts above) to use the meta: <meta name="Robots" content="follow, noindex"> on ALL pages (category navigation, tag clouds, sitemaps…) with the exception of your index page and your REAL content pages.
Which, as it was suggested (or as I understood it), would accomplish two things:
1) It would still give you the benefit of the onsite navigation PR flow that is followed on the noindex-ed pages, however (as it was suggested) that by not indexing those pages, it would flow more PR to your real content pages.
2) And leave room in the main index for more of your site to get bailed out of the supplemental index.
Has anyone tried this? Results?