Blogs are good because they notify services such as pingoat, weblog, blo.gs, pingomatic (to name a few of the larger ones) that your blog has been updated. This ‘can’ help your blog get spidered, but is not necessarily true. Depends upon if those services feel your blog is spammy or not.
Inbound links are going to help determine if you get spidered, in reality. So – if you have a good inbound link (like a link on a PR3-5 site) then you will get spidered.
Since that link is probably to your homepage, then you would want to make sure your homepage either:
1. Links to the blog
2. Is the blog
Blogs, by nature, have an internal link structure such that the WHOLE blog (i.e., all your blog postings) will get spidered. This is because there are links to all posts structurally.
I hope this helps you make sense of things.
Basically, as long as you have inbound links from reputable sites – you will get spidered. And that doesn’t matter whether you have a blog or a regular site.
So let’s say you write multpile blog pages but don’t interlink them, do you think they are still structurally linked by the blog host, and thus be favorable for SE spidering?