First - there is no pressing need to upgrade. If you're curious, or think some of the updates of fixes are pertinent to you, check the release notes.
While the update is fine, several extensions which may affect you may need to be upgraded:
If you upgrade mercurial to version 2.3, and you experience problems (for example, "hg status" in one of your repositories fails) check your .hgrc (or _hgrc) file to see if you have either of the above extensions. If commenting them out solves your problems, then you should upgrade those extensions.
Details on the issue: