Exactly which data is exposed for each provider?
According to slide 2, all of it. You might be confusing this with yesterday's Verizon story, which was "only" metadata -- caller, sender, time, and duration. This one is "actual" data -- email content, chat text, audio/video of VoIP calls.
(From the article, there's also a parallel NSA program (BLARNEY) that collects metadata only. I don't know why there's two of them).