I'd like to see it, but I have a hard time buying that this could happen. There is a lot of history and inertia at play with MS, that argues against them embracing an Open world.

I actually think Yahoo could be a bit of a dark horse here, but it's hard to guess where Marissa Mayer's head is at in this regard. Yahoo have actually done some cool stuff, in terms of Open Standards and Open Source. They were early with embracing RDFa and Microformats, for example, and some cool OSS code has come from Yahoo, including, IIRC, Hadoop. But obviously a lot has changed at Yahoo since then, so I dunno what to think about them right now.