I've just updated the permalink structure of the URLs for this blog.
Previously I was using the 'month and name' configuration for each post, i.e. this post would be "/2012/05/post-name".
My main problem with this structure was the impersonal tone it set for each post. Rather than each post being unique, important, and self-contained, the numerical structure set a very ordered tone for the posts. That being that each post was sequential and the order held some importance, when in reality that was far from true.
Keeping the URL scheme as just "/post-name" will now put the focus on the content and not the blog as a whole. Often-times I update posts and at that point I always ask myself, "Should I update the URL as well?". Also I find it much more important to know when a post was last updated than when it was first created. Look to a theme change to reflect that desire.
On a technical note I used the following post by Yoast to help with my URL migration. This way old URLs won't point to dead 404 pages and users will still be able to see the content they requested.