Let's start out by saying that hell would likely freeze over before this happened but then I can recall just a few years ago someone saying the same thing about Apple moving to Intel or ever again licensing Microsoft technology at all and currently the MacOS runs on Intel and Apple has licensed Active Sync from Microsoft. So it shouldn't be surprising that impossible things can happen between these two companies.
Apple vs. Microsoft Core Differences
While Steve Ballmer and Steve Jobs are often compared to each other the reality is both firms are as dramatically different as their CEOs are. Microsoft at its core is an operating system and tools company, it is at its strongest when it is selling things that others turn into solutions and weakest as a complete product company.
Apple, on the other hand, is a product company and it is stronger the more control it has over the total product. For instance, with the iPhone they control the hardware, software, user experience, most of the channel, the gate that allows applications in, and virtually all of the user experience. It is no surprise that this is one of their most popular products (as measured by the lines that form outside of the stores that sell them). Some could argue the iPod is more popular given Apple effectively owns the MP3 player market and their control over that platform seems even more complete.
Microsoft's most popular products, in terms of volume and revenue are traditionally Windows, Windows Server, and Office. The closest thing to a product is Office and it currently is the most at risk of competitive displacement from Google Apps. The server business, for much of the last decade, has been Microsoft's strongest unit and it is built on their core OS and tools model.
They are really very different companies, it is unlikely that Apple will ever really do much damage to Microsoft (other than the ads) and Microsoft's impact on Apple's iPod or iPhone efforts, so far, has been minor at best.
In the early years the two companies partnered. for a while and when Steve Jobs came back Bill Gates actually helped him out showcasing that the two firms could collaborate. Granted, this time Apple is in vastly better shape. But why would they partner?
Google: The Enemy of my Enemy…
Google represents a real threat to both companies because it is working to change the fundamental model that underlies the margins both Microsoft and Apple live under. Google believes in commodity hardware, advertising funded free software, and the web as a platform and once 4G becomes wide spread, Google's model should reach a point that they could largely displace both firms.
For Apple the Android platform and the Droid phone, which is currently getting more buzz by my measure than the iPhone is a wakeup call, and for Microsoft, comments from the Obama administration about moving to a Google like solution for the US government and the move by Los Angeles which dovetails with it could form the foundation large Google driven competitive displacement. These both indicate that Google is a growing threat to both companies.
It won't seem long before both Apple and Microsoft suddenly decide that pounding on each other works to Google's advantage and that maybe they should cooperate in the face of this common threat. Granted, with an anti-trust cloud over all three firms what any of them can do cooperatively is limited. This changing dynamic could shift both firms to partner with each other to better face the growing threat represented by Google.
Wrapping Up: Running Windows 7 on a Mac
Of course whether Apple licenses this or not last week VMware servers were brought to their knees as a result of downloads for Fusion 3.0 a product that is used to run Windows on Mac hardware. This would suggest that an incredibly large number of recent Apple customers are putting Windows 7 on their Macs anyway and not waiting for Apple to license the product from Microsoft.
Somehow I don't expect this to make it into a Mac vs. PC commercial, the thought of the Mac guy wearing an "I'm a PC" T-Shirt is a little disturbing. But then if you take into account Psystar's Rebel EFI utility that lets you run Snow Leopard on a regular PC you could even get to a more disturbing shot of the PC guy with an "I'm a Mac" T-Shirt. Of course, more disturbing for both companies would be that Google had 80 percent of the PC market and both guys end up wearing Google t-shirts.
Wouldn't it be interesting if you could run either Windows or the MacOS on the hardware you wanted? Well you can. Now what if both companies supported that outcome? Google's strategy is to render both operating systems irrelevant and perhaps the best way to avoid that is for both Apple and Microsoft to work together to make sure that, by working better together, they never can be.