I thought it was pretty obvious that the event would be about the evolution and transformation of the Sprint network. The giant celll phone tower on the announcement and the use of the word "connecting" seem to all but give that away (at least in my mind). I didn't find anything at all mysterious about the announcement and am confused as to why anyone would, especially as mid 2014 has long been Sprint's publicly announced goal of largely completing network vision's first phase.
Sprint has now mostly completed a massive project on a national scale and, just as a reminder, we live in a big ass country. They should RECEIVE NOTHING SHORT OF A STANDING OVATION FOR THEIR EFFORTS. I know that might be hard for some people to swallow but, just because you're one of the unfortunate few who has yet to see Network Vision bear fruit in your particular burg, town or ville doesn't mean that the OVERWHELMING MAJORITY of the U.S. isn't already enjoying a greatly improved network. Even with the latest (and possibly unforseen) issues with ecsfb on b26, the network is exponentially faster and more reliable in nearly every major and mid size city across the country (and even many of the areas in between).
This, I would contend, is worthy of celebration. And I would theorize that's exactly what we'll see at the event. There could be more (related to Framily or otherwise) but the achievements in modernizing the network will likely take center stage.