A very special thanks to Karried for the following information. Today and as per the GameSpot E3 schedule Injustice is to be on stream by 6PM PST. We would recommend tuning in by 5PM PST just in case and so you don't miss anything. The details are slim as to what we'll be seeing, whether anything new of just a refresh of information perhaps to those who missed it the first time. However, be sure to tune in to the Game Spot stream via this link by 5PM PST today to see what's good!
Source: Karried's thread
Shoutout to TRMK for the extra assistance as well!
Injustice E3 Demo Today on GameSpot Stream 5-6PM PST