Google will maintain their market lead over Apple because today's customers are concerned with what they are getting for their hard-earned dollars, and not just concerned with a brand name. Apple's products can cost almost double than Google's for devices such as tablets and smart phones. This business model isn't sustainable.
Google is a very powerful company. They are known to treat their employees better, they own half of the internet (including YouTube), and they are a really powerful source. Apple has been messing up a lot lately and I think that Google just saw this opportunity to take that status from them and did it.
Even though Apple has just as much developing technology as Google and the same amount of resources, Google tends to be the more user-friendly company. Apple is most popular for their phones and laptops, but Google has a lot more products that have popularity. Also, Google products tend to be significantly less expensive than Apple products.
Yes, Google will maintain its market lead over Apple. In fact, the purchase of Google's search engine by Apple for its iPhone is a clear indication that Google is making strides. Also, Google has recently implemented a test program to screen out search results of search terms related to terrorism and extremism, by providing the opposite results of what users are searching - anti-radicalism links instead.