Microsoft won't be able to beat Google is my opinion. Microsoft's bing merged with Yahoo back in Nov. to try to maintain some standing. I think the move is too little too late. Also consider that Google picked up a few patents from IBM (I think it was IBM). Those patents may be able to launch Google beyond the reach of any other engines for a long long time to come, if not forever.
Microsoft won't surpass Google when it comes to traffic & popularity. But honestly, Microsoft is not only with search engine popularity. It also deals with software manufacturing.
Microsoft has been way ahead of the pack for years, and I doubt that anyone will ever catch up. Microsoft security sucks so badly that there have been well over a million malware programs written that take advantage of their security flaws. I seriously doubt that Google or anyone else will ever have that many malware issues. In other words, I don't think Google will ever best Microsoft.
i think that Yahoo should buy Ford, that Ford should buy Microsoft, that Microsoft should buy Boeing, that Boeing should buy Intel, that Intel should buy General Electric, and that General Electric should buy Yahoo.