I often get asked, if there is an easy way to get notifications for Patches and Hotfixes for SQL Server. Generally I recommend people keep an eye on http://sqlserverbuilds.blogspot.com. However I just came across another site that can be used, http://blogs.msdn.com/b/sqlreleaseservices/default.aspx. Unlike the SQL Server Builds website, you can subscribe to RSS feed on MSDN site, this way whenever Microsoft releases update you can review it right away. I really give kudos to who ever is maintain SQL Server Builds website; by far the most compressive and easy to use site for SQL Server build details. So both sites in conjunction, I think are beneficial links to have in your favorites for patching and hotfix release information.
As Microsoft best practices we recommend you keep your servers up-to-date on latest service pack level. It can be challenging in my scenarios; however, if you know what fixes are being released and what are their impact. Then you can have an proactive discussion with business owner and management on why certain patch level is required.
For example, lets say the patch required because of memory leak, or corruption fix, etc. These kind of patches you don’t want to wait for until you run into issue, we need to be proactive about addressing this to maximum the availability and uptime for service provided by SQL Server.
SQL Canada (SQLCAN) 
Mohit,
Aaron Bertrand of SQL Sentry is a great resource about the latest CU’s. See him at http://blogs.sqlsentry.com/ and http://sqlblog.com/blogs/aaron_bertrand/default.aspx
Chris
Nice thanks :). I tried posting about every CU and HOTFIX; as I have internal notification. However I found it very difficult to keep up with it, even though we do not release CU, Patches, and HOTFIX that often. Really glad for the link thank-you :).
New CU’s for SQL2012 SP1 and SP2 now out.