I was far more disappointed by the use of starfighters for atmospheric maneuvers. There's are reasons you don't have many dogfights in atmospheres with fighters like that. They simply aren't designed for that sort of thing. I was also a little disappointed by the use of the old Rebellion symbol rather than the updated and more detailed one which the EU used for the New Republic, or even the GA symbol. I understand they aren't using the same canon, but they are having time pass at least.
The trooper did seem rather pathetic in the clip we had, but I think we need more of the context to really judge his behavior. Still, they'll need to really excuse a trooper (assuming he's not some crummy rebel spy) snapping like that. Also, only the earliest troopers were clones; once the empire took over they opened recruitment. Carida (sp) is a whole planet devoted to training regular imperial citizens for the stormtrooper corps. (Pretty sure Jango Fett was supposed to be New Zealander, not Hispanic too)
The Sith guy's saber is a bit silly if you ask me, but it won't be a deal-breaker or anything. I can't imagine it being a good thing for toy marketing though. More extendable parts on toy sabers? I don't think so. Seriously hurts their merchandising if that's really what they want to go with. Of course, other elements of the EU have weapons like a light-whip, so who knows what they'll incorporate tech-wise.
All in all, as a teaser, I'm unimpressed, but I want to at least see a theatrical trailer before I make any serious judgments.