Microsoft just released the Service Pack 2 for Office 2010. It is a roll-up of all previous updates and bug fixes. You can read the official description and improvements here. The 32-bit version weights 638.2 MB and the 64-bit version is 730.4 MB.
You can keep your Office installation up to date by using the Updates folder. You can read more about this here.
To extract an Office update, including Service Packs, use the following command:
The folder where the files will be extracted to needs to exist or the process will fail. Once you are done extracting files from all the updates, copy them to the Updates folder. If this is not the first time you are doing this, overwrite any file when prompted.
The next time you install Office the updates will be installed as well, saving you precious time.