Oh yes, the tag filter will be useful.

One suggestion for the post editor: allow for usage of a custom signature, so users don't have to keep copy and pasting their "signature" at the bottom. It'll be even better if I can create a custom signature that offers users "My Recent Posts in this Area" and then generate the latest 3 links with that tag on my blog. Now that will really be useful and make me want to use OnePlace.