The first gameplay footage for Metal Gear Rising: Revengance is a cut above the trailer. The playthrough of the first part of the e3 exclusive demo showcases the parts of Rising that have long been teased. Namely that you can cut things up into a fine puree if you so desire, but doing that requires Blade Mode.
Like any awesome slowed down moment, it consumes Raiden's fuel cell surprisingly fast in the demo. While the main cell seems to refill over time, the additional ones require Raiden to consume other fuel cells as he did in the second teaser before Platinum Games got their hands on the franchise. The other possible spoiler came when describing the game that Rising takes place after Metal Gear Solid 4 and hints that Raiden doesn't have the family life that he was supposed to.
The other feature teased is his Ninja Run ability, "key to all cyborgs" the unknown Russian handler informs Raiden. It's basically a power-suck that allows Raiden to dodge bullets, run up walls and pretend to be the Flash as sparks shoot from his legs.
Revengance may be a massive shift from the previous Metal Gear, but it definitely looks to fit well with Platinum Games' destruction porn mentality.