Inexpensive Price Point
This is where Microsoft should take notice. The differences between Apple and Microsoft are huge, however the major one that should be noted is that Apple is a hardware company, whereas Microsoft is a software company. This is why I think Microsoft will adopt some sort of App Store in the future. Since Apple takes 30% of the revenue of every app sold in the App Store, they can do things like offer Lion for an extremely low price of $29.99. When there was speculation on the price, I actually firmly believed that the software would basically be free since they make so much money on the apps and the hardware.
If Microsoft wants a strong home consumer adoption of Windows 8, they will have to offer the software at a lower price than they are even offering it for now. Most people do not get a new operating system for their machine until they purchase a new computer. On the Mac side of things, the newest operating systems are often widely adopted by users. Running the latest operating systems has more benefits than just making Microsoft and Apple more money; they provide the latest security updates and the best-optimized code and new features. Legacy support will always be an issue with Microsoft software, but a lower price point will definitely encourage people who would not normally upgrade to upgrade.