Gartner’s four-year forecast suspects that the iPad will still be the dominant player come 2015, expecting 146 million iPad sales that year, compared to 116 million for Android devices. That leaves Android as a close runner-up in the future, but right now we’re already seeing Android playing catch up.

Looking at connected devices at large, Millennial Media’s August report shows Android as the clear winner, with 54 percent compared to iOS’s 28 percent market share. And Android smartphones and devices are growing their impressions on Millennial’s network at a rate of 48 percent month-over-month, while iOS impressions remained relatively flat. Connected devices and feature phones (pretty much everything but smartphones) each took 14 percent of network impressions for August, leaving smartphones to rule 72 percent of the market share. It’s still a pretty broad outlook for Android vs iOS when it comes to the whole of connected devices, but it offers a glimpse of the big picture as mobile devices become more diversified.

One notable unifying factor amongst connected devices, however, is the use of Wi-Fi. About 32 percent of all Millennial’s impressions came over Wi-Fi, with smartphones taking up nearly 60 percent of that market. Connected devices racked up 34 percent of Wi-Fi impressions, hinting at the connectivity behavior of the U.S. It’s no surprise that Wi-Fi networks are becoming influential beacons as more devices crave data connections.

Facebook Timeline optimized for mobile

So what do we need to be connected for? News, entertainment and social networking, of course. And social networking in particular is seeing an interesting shift to mobile. It’s expected that social networking will become a predominately mobile activity, surpassing 550 million users by the end of this year, and 1.7 billion by 2016. That’s great news for Facebook, which has big plans for mobile. The network already boasts 350 million mobile users, and Facebook’s making an appeal to those users with Timeline, a new feature announced at the f8 conference yesterday.

Replacing your Profile and Wall, the Timeline is a digital scrapbook of important highlights in your life, which will aggregate the “notable” updates over time. Facebook was smart to design a mobile version right out the gate, but that’s a lot of scrolling and media to load for a mobile user. No wonder Wi-Fi is becoming so important for connected devices, data plans these days are becoming rather limited. As is the case with many thoughtful developers, Facebook takes the Timeline media into consideration, showing as much content without overloading a user’s data subscription.

Facebook will be collapsing most of the content on the backend, so you can easily view a friend’s mobile Timeline. The older data wont load until it’s actually accessed, and the mobile app will have a “scrubber,” which is the scrolling button for you to use in order to access that content.