Answer :
The simple answer is yes, but google dose not give much value to the blog comment links, but in fact Google gives much value to the links in between the blog post. Whatever blog commenting is long time processing and very use full for promote your website, if you can get a link from dofollow blog with high PR that's more wroth than a normal nofollow link cause nofollow links will not passing links juice to your site.
Don't forget to write comment's in relevant sites because irrelevant links may hurts your site rankings.Also write something useful and don't try to spam blogs!