We're doing a complete update to the link package, so keep an eye out for that

On blog comments - you don't want to limit your backlink strategy to just that. The key to effective link building is variation. Definitely mix in some directories, article marketing, guest blog posts, forum signatures, etc.

On the nofollow/dofollow issue, Michelle MacPhearson did a test recently and got a brand new site indexed in Google with only nofollow links. A lot of people think the search engines don't follow nofollow links, but that's not the case. They are supposed to be used for not passing PageRank from page to page, but the search engines do still follow them.

See the Nofollow Attribute section in this Link Building 101 post.