Yes, over 1000 Americans have been killed in Afghanistan, over 10 times as many as during the Gulf War. Those numbers were as of a month ago, its probably pretty much the same now.
Polling showed over 50% favor the war against Iraq until qualifications such as loss of life come into play, then the polling numbers drastically change. I havent been able to find "expert" of any type who believes regime change in Iraq wont result in thousands of American deaths. Unlike the Gulf War which was fought mostly in the desert, to our advantage, taking out Saddam would require urban warfare, very costly to both sides. Read Bush Sr's own comments on why he didnt invade Iraq.