Cool idea! Very, veeery limited amount of cinemas involved (40 between US and Canada? Aren't there, like...4,000 in total in all North America), but it can be comprehensible, since this is the first time they do it, and maybe they've estimated that 40 theatres were enough for the whole amount of people going, so maybe, next year it'll be over 100 if this will have a good success. Still, I like it! Hopefully, Sony delivers at E3, with a good amount of content for 2015 and, at least, 1 more title for this year (strictly speaking about first parties, here, not third parties: the current events made me quite worried about their output, but I hope we'll get a look at what's doing SCE ).
IMHO, this would work better with a pre-recorded thing, since that could be "arranged" as a movie, made more entertaining, without dead moments (which is also why I'm very curious to see how Nintendo's going to do with the Digital Event, since it'll be different from a Direct), but when the bombs are dropped, the cinemas will still explode with laughters and joy
P.S. Wait, Ustream? Not YouTube? >_>