We have tracked down the URL for downloading Team Explorer 2008 from microsoft.com (when I first wrote the post I wrote that I didn't know where it was).  The url is: http://www.microsoft.com/downloads/details.aspx?familyid=0ED12659-3D41-4420-BBB0-A46E51BFCA86&displaylang=en

I have since updated the original post here: http://blogs.msdn.com/bharry/archive/2007/11/22/2008-installation-questions.aspx so that future readers can find it and not have to thread all of the updates together.

Remember to use Team Explorer 2008, you need a 2008 TFS CAL.  The only way you could have that right now is if you bought your CAL with Software Assurance (SA).  You will be able to purchase new CALs if you need to in Jan.  Of course, if you bought a Team System client SKU with MSDN, then your MSDN subscription is your Software Assurance and you don't need the Team Explorer download because you can just download your Team System Client SKU and you will find Team Explorer included.