
After reading through a couple press releases, I found something very interesting in the PlayStation Plus press release. At the bottom of this press release it says:
"PlayStation users can purchase PlayStation Plus membership through PlayStation Store on PS3 only. Users need to install PS3 system software version 3.40, which will be released on June 22nd, to enjoy PlayStation Plus."
So it looks like PS3 owners will be receiving a new PS3 firmware update June 22nd. It would also make sense that this would be the update which would include cross-game chat.
On Sony's official Netherlands website, this is written:
"Cross-game Voice Chat: invite your friends to chat online no matter what game you're all playing, even if they aren't members of PlayStation Plus."
UPDATE: It seems as if Sony has removed this. I personally think Sony did this on purpose just to get the news out there. I thought it was weird when it was the only English part of the page. Read more for picture proof for all of the doubters out there.