My startup uses a wordpress-based website - since last September - which looks more like a blog than a startup home page (which has been ok so far since we started out small - bootstrapping and later getting getting some revenue and funding).
In order to get startup web site visibility tech-related blog posts (in average 2-3 postings a month) have been the main source (with del.icio.us, twitter, reddit, hacker news and google as the main traffic drivers).
We will probably eventually change to a more business like website, but blog-like will do for now.
Conclusion: unless you have extremely viral services, your startup blog is likely to drive (much) more traffic than the rest of your startup website.