The W3C is forging ahead with it's binary representation standard, XOP. They will be using it to optimize SOAP transmission. It will be interesting to see the impact on Indigo. Omri, a PM on Indigo, seems pretty negative on creating a standard. Will Microsoft support the emerging standard? I thing they will have to if it gains steam. The real question it will they support it for .NET <-> .NET transmissions.
Correction: Simon Fell explained that this is incorrect. See my new post to find that XOP is really binary attachements!