Yes, I think once Google+ releases their APIs (what is taking them so long) one can see hundreds of new apps popping up - not just for the web but also for the mobile version. Also the group video chat they have (hangouts) is actually Google+'s killer app - can already imagine many cool apps using it (customer support, training etc).
I think one of the advantages that Apple has over every other platform is that designers use Apple for work which builds brand loyalty to its products and platform. Thus, a good portion of the people who are creating will do so for the platform that they care about, especially one that prioritizes industrial and interactive design. And before, I would've just suggested it's just designers but over the past few years years, I've witnessed plenty of SF/NY developers who use Apple computers and iPhones for the same reasons.
The fact that it is a closed-system IS it's advantage: there is quality control across the board from the apps to the phone the user is viewing it on. And quite frankly, I prefer designing for the iPhone and iPad because of the consistency of sizing and proportions.
But there doesn't need to be a clear winner. It's great that there is a choice for people who just want complete freedom and those who just want stuff to work well in a very polished fashion.
