Sony announced the PlayStation 4 yesterday (February 20th), without actually show it off. Instead, you're only given vague information about the upcoming system, some game announcements, and showing off the controller (this was probably a given since there were leaks online prior to the announcement). I am interested in Diablo III, but will it require its terrible "always online" requirement? I hope not. That was the one reason why I refuse to give Blizzard any more of my money.
Why should you be interested in these systems? Outside of gaming, these machines make amazing media boxes for your television. Most people (like me) use them to watch all my media or listen to all my music via a Network Attached Storage (NAS).
Based on PS3's already established "Apps" model, I wouldn't be surprised to see more video or music-related apps. Right now, you can get "Music Unlimited", which is a subscription-based model. As I wrote in my review, I think $10 is too much to ask to pay, but the $4 model won't get you very far.
Below is a comparison chart between the 'next' generation consoles. Since the Xbox has not been announced, all the information I listed below are pretty much rumors - based on a development kit via Kotaku.
Again, I should stress that much of the Xbox information are rumors.
I was afraid that the PS4 will require an always online connection - but Sony's game studios chief, Shuhei Yoshida said it doesn't have to be online. Xbox, on the other hand, is said to require online to play all their games. They have not squash the rumor, and I actually believe that Xbox will require online - after all, most PC games require online activation in order to run it. Remember: this is the same company that requires you to pay $80 a year to have the ability to watch YouTube.
Other interesting note is that both consoles can quietly install games in the background while you play your game. The PS4 has a duo chip, with one of the chip decided to such tasks - while the Xbox will also have a dedicated "block".