Cumulative Update Package 3 has been made available in KB #960484. This will bring your SQL Server 2008 instance(s) up to build 10.0.1787.0.
The most interesting fix for me was the one mentioned in KB #958760: "FIX: You may experience issues when you try to expand the Databases node in SQL Server Management Studio, or the sp_spaceused stored procedure takes a long time to run in SQL Server 2008"… this is an issue that bit a LOT of people when SQL Server 2008 was first released. See Connect items #354291, #362646, #383715, #354322, an entry by Desirée Harris @ OrcsWeb, and my previous blog post about the issue. At the time there were dozens of other blog posts about this issue that I was simply too lazy to fetch when I was posting this entry.
There are some other interesting fixes as well; I suggest checking out the KB article above to see if you are affected. As always, please request the correct patch files for your platform, and test before deploying this patch to production!