In this article, Why Apple Will Buy BlackBerry the author puts forward some convincing reasons why we might expect Apple to end up buying Blackberry.
First, the $5 billion or so it would cost is chicken feed for Apple. They currently have more than $150 billion in cash.
Second, buying BB would give them a significantly larger foothold in the corporate space, and they would be buying Blackberry’s reputation for security.
Third, they would lock up the hundreds (thousands?) of patents owned by Blackberry.
Fourth, such a purchase would keep the BB assets out of the hands of a current or potential competitor like Microsoft or Google.
I don’t want this to happen, and don’t think it will, but the logic is pretty compelling.