Cloaking devices? Oh yeah, we can totally do that. Telekinesis? Suuure! In this video, Real Actual Scientist-mans Dr. Michio Kaku, speaking more like a futurist and less like a physicist, tackles the plausibility of what you see in Mass Effect.

I recommend getting good and high for the discussion of dark matter, although he does point out that "when you put negative matter into Einstein's equations," - i.e. divide by zero!! (!!!) - they "curl up into knots." And hedging that the big unknown it creates will be more good than bad we can get stuff like faster-than-light travel and real-time pan-galaxy communications.

The Science of Mass Effect 2 [Game Trailers]