Microsoft has released Cumulative Update 5 for SQL Server 2008 Service Pack 1. You can go here to request the hotfix from Microsoft. It typically takes just a few minutes for them to send you the download link and password, then you have to download and unzip with the password. This CU is Build 2746, and there are about 35 fixes, including ones for SSMS, database mirroring, SSIS, etc.
They also released CU8 for SQL Server 2008 RTM, which is Build 1823. If you are still on the RTM branch, you should start thinking about getting on the SP1 branch, since Microsoft is going to stop mainstream support for the RTM branch early next year (if memory serves).