Apple has always kept most of their acquisitions pretty small and to companies that are TYPICALLY not publicly traded and they usually go for companies that have technology that is key for future business whether it's s/w and/or h/w based. They do this for a variety of reasons. It doesn't cost much to buy a company for tens or hundreds of millions, they are kept under the radar of the SEC and competitors. Buying these big stock deals is not only pricey, but they sometimes don't offer much other than a big headache and it can sometimes take 10 to 40 years to fully recoup the money. If you look at the P/E ratio and how much cash on hand/long term/short term cash, the time it takes to recoup the money isn't worth it. Let me give you an example.
Let's say a company had a P/E ratio of 35 and Apple paid $10 Billion, and the company had $1 Billion in cash. So, it actually costs Apple $9 Bil of actual cash, but it might take 30 years or so since the company they are buying is already sold very high in relationship the amount they bring in on a yearly basis.
Apple has to look at the business in what they are buying, what they need to keep, etc.
Why would Apple need Nokia? For patents? If Microsoft buys the company and the associated patents, then Apple may already have access to them due to their agreement with MS. Nokia has some mfg/assembly capabilities. Well, to switch Nokia production lines over to Apple would take a while, while it's probably easier and faster to add production in China with Foxconn, Pegatron, etc. so that's not a reason. So, what's left over? to continue selling and supporting existing Nokia products for several years? Apple doesn't want that headache. What other reason could there be? To prevent someone else buying the company? No profit in that.
There are only a handful of publicly companies that I could see a potential buyout for Apple that would make sense. But there are still too many roadblocks in the process.
I think it's better for the most part to stick with smaller technology companies where they can gobble up and actually use the technology and people to create future products.
It's really hard to resurrect a large failing company. HP failed with Palm, Dell's failing with Wyse. I think it would be pretty close to impossible to resurrect Blackberry at this point. I honestly don't know what they have in terms of patents that actually worth buying.
Apple put a bid in on Palm. It was rumored Apple's plan was to run it as an independent subsidiary and allow it to continue selling phones. It would have been brilliant if it worked out because it would have allowed Apple to push the Palm OS on carriers in the US that Apple was not allowed to sell the iPhone because of its five year deal with AT&T. This likely would have put a big hurt on Android back when Palm OS was far superior.