I think Apple will make a big acquisition within the next 2 years. The most likely candidate is RIM for their patents, enterprise technologies, hardware people and cloud experience. The software they make is generally good, but they have a total lack of strategy and business coherence. They can probably be picked up quite cheaply within the next 18-24 months, and healthy competition within the mobile market together with RIM's declining influence help the antitrust side of the deal.
I think Amazon are big contenders, too. They have massive cloud experience, and would complete Apple's media ecosystem. The big danger with buying competitors is that you inevitably kill the competing product, and most of the company's profit and soul. With amazon, if the Kindle is essential to the business, the deal just won't work. The thing is, IIRC, Amazon do not actually make substantial profits on the Kindle. What with Whispersync and those e-ink displays, margins are thin or even negative. But that's ok, because like games consoles, Kindles are portals to Amazon products with much high margins to compensate. E-books could easily be transferred to Apple's existing products. Perhaps there could be room for an e-ink based reader running iOS, but it's difficult to tell how to proceed. The antitrust side is definitely tighter, but I don't think it's impossible to get a deal like this done (perhaps involving spinning off the Kindle business to find another bookstore). Apple's interest in online purchasing is small (it's already very easy - not calling out for reinvention), but they have shown that they can do offline and online retail and make a huge success off it, so who knows?
At about the same likeliness is Nokia. Like RIM, their market share is falling, their customer loyalty (the last big thing they had going for them) shredded. The patent aspect is obviously huge here, as is their software and hardware experience, cloud services (e.g. mapping services), distribution and sales. Apple would probably spin off some of their more technical (e.g. network equipment) businesses to keep the Nokia brand. Acquiring such a big european brand might not be that easy, especially considering how slowly yet aggressively the european commission pursues antitrust enquiries. Apple also likes to keep their people close together. There's no reason it couldn't work, but it's one of the reasons Canada's RIM is far more likely a target than Nokia.
Wow, that ended up being really long. Interesting times in the industry, I suppose.