Saw this yesterday.
Loved the small reference to Cap America ("trying the super soldiers before") and loved the action and the final battle.
Liv Tyler I think was a little miscast. Edward Norton was great. Tim Roth was fantastic, and well, I like William Hurt in anything he does.
Cameo by Tony Stark was freaking awesome as well, and I'm also glad that Iron Man looks like it will nail $300,000,000 domestically. That movie deserves that good of a box office. I only hope the Hulk can score $160-$175 million domestically to bolster Marvel's coffers. I like what they are doing with their franchises. Even if I'm worried about the upcoming Punisher sequel.
... which reminds me...
How can these people keep fucking up the Punisher? HE IS THE PUNISHER. He was like my favorite guy when I was growing up just because he was a regular dude who blew away everyone. His battles with superheroes and villains alike made him one of the most badass characters ever.
Frankly, the Punisher should have had cameos in some of Marvel's other movies just to be more true to the old school universe.
edit: Cool tidbit -- http://www.boxofficemojo.com/alltime/domestic.htm
-- Iron Man could bust into the top 25 All-Time domestic grossers by the end of this upcoming weekend. That'd be pretty cool for Favreau and Downey Jr.