Overnight, a few updates for Windows 7 Beta build 7000 have been released on Microsoft Update and Windows Update.
One of the updates is a patch for Internet Explorer 8, to give it some of the stability updates that have been released in Internet Explorer 8 Release Candidate (RC). The previously released IE 8 RC can not be installed on Windows 7 Beta. Windows 7 RC will have later version of Internet Explorer 8 in it when it is released. Further information on the IE 8 update can be found on the IEBlog.
The other updates (5 in total) are Windows 7 Test Updates, to verify that the various patching mechanisms work correctly. They do not fix anything, but will give the product team good telemetric data on the update experience. More information on the Microsoft Update Blog.
Whilst you are updating, you may notice a number of Optional Updates. These are generally updates to hardware drivers that 3rd party Manufacturers have released.
As part of the beta process, Microsoft does recommend you install all the updates so that good feedback can be collated on the improvements and the update processes.