After quite a bit of work and discussion, we now have Microsoft MASM available on the web (and there were some on this board that helped drive the discussions).
It does require VC Express SKU, which has no cost (if you have the other Visual Studio SKUs, they already include MASM). The link is at: http://www.microsoft.com/downloads/details.aspx?FamilyId=7A1C9DA0-0510-44A2-B042-7EF370530C64&displaylang=en
Note that it is for non-commercial use only. Which means you can use it build hobby products, but nothing that you would sell or use to maintain an enterprise or such things. But obviously ideal for the hobbyist or those learning assembly language programming.
Feel free to write if you have any questions,
Kang Su Gatlin
Visual C++ Program Manager
kanggatl AT microsoft DOT com