I just recently upgraded to WordPress 2.3.2 and found out about the update reminder for newer version of plugin is available. This reminder actually reminds you of the WordPress version as well. Seeing that notice, now I am at version 2.3.3.
Upgrading wordpress has always been easy, but I am a little lazy to upgrade when they have another upgrade too soon. As it is most probably security issue, which require me to do the update too. For those who are even lazier could try WordPress Auto Update (I have tried it on another site, but seem to face some problem, I will search for the solutions).
ya.. i only replaced the XML-RPC file.
If not mistaken, XML-RPC is used to connect with external tools like Live Writer or other writing tools. Correct my if I am wrong.