OK so two websites are rumormongering this about now.... but when you think about it, it makes sense! Microsoft's only way to compete in the smartphone arena is to buy out a company like RIM, since RIM's Blackberries already are microsoft-savvy (i.e. exchange) and business-savvy devices.
Hardly. RIM made 6 Billion dollars last year. Their market cap is 31 billion. Not so say that makes it any more of less possible, but the EU would never approve the sale much less the Canadian Government.
Microsoft has no reason to acquire RIM - they never have been in the hand-held phone business. Furhtermore you have to remember:
1) Microsoft has their own phone software platform, they aren't going to dump it since there is huge corporate need for its support.
2) MS also has another phone system - Danger
3) MS already has mail acquisition technology of its own that already directly interfaces with Exchange and does not require a dedicated NOC that RIM uses.
4) With what RIM is trading at, they could afford to buy out Yahoo at twice the current share - and their web business is in far more a world of hurt than their mobile business.
The only thing that MS could gain from RIM is selling handsets - otherwise they would obtain competing technologies that have nothing to do with each other. I just don't see it happening anymore than the Yahoo deal would.