The trend is your friend, one of the first things anyone who's suffered a trader learns. It's not a case of how high or low something is, but where it is going to be relative to it's current place.
Press and Markets get this (the former to a lesser extent true) but the fear is that Apple have had their Halcyon days. Originally Apple didn't need to worry about such issues as apps, they had the first phone device with a web browser that people really spoke about liking. Heck they didn't even have GPS dispite most feature phones in the UK having it with maps.
A lot of analyists are asking, rightly so, why is Apple able to keep making such money, now the market is cramped. Want a better camera, buy the 920, want a better screen? Buy the HTC, want a larger phone, buy the S4, want a smaller phone buy the. Hell I don't even know, but you get where I'm going with this.
The brand of the iPhone people fear to be falling. In the old days of Windows 3.1 domination, the software took months to years to write. Most of them now adays have little if anything more than weeks of platform specific code. The alternate marketplace is huge, due to the size of the global market place. Hell a friend was just telling me how he thinks he'll make a profit porting to the new blackberry, despite it having very low uptake here in London.
These notions lend people to conclude that what is currently happening with Apple might not be sustainable. Gruber has been consistently wrong the last few months (in fact he is always as he predicts little but Apple growth) with regards to the decrease in share price and failure to develop new market share.
tldr; It might not be Apple vs Google. But neither are expanding their userbase rapidily, without encrouging on the other.