WordPress 2.1 has been released recently. I upgraded today and as always, it was a more or less a painless procedure. Merely overwrite your existing WordPress files with the new package and then run the wp-admin/upgrade.php script. It's as simple as that. Even if you use a few plugins you needn't be too worried. I guess most plugins that work in 2.0.x will work in 2.1.

Traditionally WordPress upgrades have never been radical. Most changes and enhancements to this extremely popular and stable blogging platform come in slow, incremental steps and this upgrade is no different. If you've been using the 2.0.x version, you'd not notice too many external changes. However, since there are more than 500 bug fixes, it would probably be a good thing to upgrade anyway.