I just signed up. Couldn't resist lol. It was smart of Sony to keep online play free as I wouldn't have signed up for PSN plus on principle if that was the case.
The thing that got me are the discounts and freebies. Over the next couple of years I will get much more than I paid for.
Just hope they give us cloud storage soon. I would freak if I lost my SFIV save file. (Too lazy to do a system backup)