Telligent have just released a service pack for Community Server 2.1. The service pack fixes a number of annoying little things (and updates the version number to 2.1.61025.1) - if you're running CS2.1 it's certainly a worthwhile upgrade.
However, it does highlight a couple of small niggles with CS. The upgrade process is very manual - you have to run a SQL Script against the remote database and upload various files to replace the old one... but there's no quick and easy way to find where you've customised the scripts and ensure that the customisations make it through the upgrade.
For me it was simple as I've very little tweaking here but for people who've really customised the look and feel of their site it's going to be a more significant update - and would scare me for the future unless the Telligent are planning to put a bit more thought into the process - both for the current 'hardcoded' approach to customisation and skinning and also for the upcoming 3.x generation that hopefully brings a new skinning model...
It would be really neat to see a PC based tool that includes FTP capabilities (to update the files) and a SQL connection (to run the scripts) - both highlighting changes (by knowing what the original vanilla code looked like and running a delta against it that can then be applied to the new version. Of course it's never going to be that simple or easy... but it would be cool