Yes. As more updates you have in your website, more relevancy for the bots your website has. Actually, if you use the Google Sitemaps, you can specify the change frequence of a specific page of the website.
My feeling is getting it indexed initially is related to having a quality link/links going to the site. If search engines do not know site is there, adding content continuously does not matter. Once search engines find site and begin indexing, frequency of updating seems to play a part in how often they spider and updated you listing in their index.
if you site is not indexed yet, updating it probably wouldn't help that much (not any more than adding links that's for sure), but spiders like it, so they'll come more often and may rank you better if you do.
The spider bot hasn't been to my page in 2 days. Maybe it didn't like what I said about it on this forum.
Not sure if this helps, but I wrote a review on a product that I could not find any real reviews for and in about a week, it was available on Google. I use Google Sitemaps. I have also been lax with updating for about a month now.
If you're using Wordpress, submit a sitemap, and then download the sitemap plugin to automatically ping Google whenever you update or add content to your blog. Google comes by faster when you tell it you have something new to feed it.