WordPress 2.8.1 is the latest release to grace the would be blogger, and from my opinion it is a necessary upgrade for almost any WordPress site. That is however if you truly understand what you might be dealing with during such an upgrade. Unfortunately, many site owners get misled into installing every plug-in they can find leading to slow load times and conflicts during upgrades. Use extreme caution upgrading to the new release if the site in question is loaded with widgets, and plug-ins.
With that scary stuff out of the way WordPress 2.8.1 is light years ahead of the pre 2.6 versions, and even 2.7. The administration panel is very well laid out with the functionality you need to keep your site up to date and running smooth. You will receive messages in your plug-in area alerting you of updates, and giving you the ability to perform the update automatically.
As you have already guessed I am not a huge fan of a bunch of widgets and plug-ins, they remind me of a one man band trying to make music. Keeping a site clean and crisp is essential to it being truly cross browser compatible and able to validate. Here are the plug-ins I believe to be essential for any 2.8.1 WordPress site.
http://wordpress.org/extend/plugins/wp-db-backup/
http://wordpress.org/extend/plugins/ozh-admin-drop-down-menu/
http://wordpress.org/extend/plugins/all-in-one-seo-pack/
http://wordpress.org/extend/plugins/sitemap-generator/
Backing up is an essential part of an upgrade or installation of any kind when dealing with anything in information technologies, make sure to back up all files and the database. WordPress has a great following with info online just a Google search away if you get into trouble. Of course I am always for hire as well.
Have a good one, and happy blogging.