Well… My opinion on upgrading WordPress to version 2.3.x may differ than others. But I say if it’s not broke don’t fix it.
New versions of WordPress might require new versions of plugins or render some plugins useless. If there are not compatible new versions of plugins available then you may not have that plugin anymore. One specific plugin that comes to mind is Ultimate Tag Warrior (UTM), I installed this all blogs prior to version 2.3. WordPress 2.3 has built-in tagging but nothing as easy to use as UTW, and while there is a new UTM plugin available it doesn’t always like running on some hosting accounts.
As far as missing out on any new things in the new version; the tagging is really all you are missing as far as functionality goes but UTW is better, in my opinion, anyway. There is also a warning about new versions of WordPress and plugins available that are shown on version 2.3.X. The last version of WordPress is 2.3.2 and it has a security patch for only version 2.3 as well.
Upgrading isn’t really hard as far as uploading all the files except some of the wp-content folder and running the upgrade file. The wp-config folder has the plugins and themes folders in it and should not be replaced or you will loose all your plugins and themes. Since the blog’s content is held in a database you really shouldn’t lose anything upgrading but precautions should be made prior to upgrading. A backup of the files and database should be made. All plugins deactivated and newer versions installed and activated one at a time after upgrading.
This can get very time intensive and actually be more work than a new installation, and since I see no real big value in upgrading (yet) as far as traffic generation and tagging goes so I haven’t posted anything about it on any of my blogs until now.
Having said I don’t think upgrading is worth it (yet) if you are running version 2.3 I do suggest you get 2.3.2 for the security fix but that is all at this point.
If you still want an upgrade Click Here to contact me and I will try to help, but given the time it takes and the low prices I charge for the initial installation I will need to be paid for my time.