It was an interesting announcement. It was rumored by one source that today's meeting was probably announcing Sony's departure from the console business (relished the thought personally), but [unfortunately] it seems that Yuta Sakurai's (Nomura financial analyst) 6-year old prediction fell through and Sony is bringing forth the PS4.
It was the first time I watched a non-E3 game-related meeting live and it was pretty cool. Two hours of incredible yet at some times familiar (remember the Agni's Philosophy demo from 2012?) bits of playstation goodness, that most likely wouldn't have been squeezed into Sony's E3 2013 conference.
The controller looks okay. Still feel a bit disappointed about a couple things about it: 1. The DualShock design is still being used. 2. The controller does not appear to be of any threat to the Wii U controller (at least), in respect to only being able to play a game off TV with the purchase of a PlayStation Vita. The "Share" feature however, is a really nice idea.
As other people here have noted, even for 2 hours the info still sounded very hush-hush (even the in-meeting audience sounded less than enthused at times).
Third-party developers sounded rather excited to be developing for PS4. Chances are we'll find out more about why developers are so excited when we see Sony's E3 conference.
Meanwhile, Microsoft and Nintendo hopefully have some really good aces up their sleeves that could help slow the roll of the PS4's holiday launch.