Ok...I finally got a chance to see Dawn of the Dead last Friday, so now I will give my thoughts. Let me start by saying that it is an excellent movie, worthy of being counted among it's predecessors as a great horror movie.
Although it is a remake of the classic, Dawn of the Dead '04 is not simply a retelling of the original story with a bigger budget and modern setting. Fans of the original will notice some similarities, but they are all done in a new and unique way. The director even uses your knowledge of the original to build suspense and take the story in a new direction at several points in the story.
Unlike the original, zombies are highly mobile (but still as dumb as rocks). I didn't know how this would work out compared to the original, but it turned out quite well. Perhaps the regular slow zombies just aren't scary anymore, and I can live with that.
The movie does not lack one thing that is important to a good zombie movie: humor. From their interesting rendition of Disturbed's "Down With the Sickness," to the relationship between Andy and Kenneth (Ving Rhames), the movie does not lack comedy, especially if you have a rather dark sense of humor.
Nevertheless, the movie does not let you forget that the mall is surrounded by relentless hordes of the undead. There is also plenty of gore, which is another key to good zombies movies. Despite having an R rating (as opposed to being unrated or NC-17), Dawn of the Dead has a respectable amount of gore.
Some people have complained about the ending; however, it makes perfect sense when you consider the original trilogy as a whole. Through subtle, yet clear references, the plot movies from Night of the Living Dead, to Dawn of the Dead, concluding with Day of the Dead. In this way it is a remake not just of the second film in the trilogy, but of all three. For fans of the original, this adds an additional layer to the already great remake.
Another possible criticism is Dawn of the Dead '04 does not really bring anything unique to the zombie-horror subgenre (even the zombie baby has been done before); but it is the combination of elements that makes the film original and unique. The environment established in the first few minutes of the movie also adds originality in its depiction of the chaos following the first stages of zombie infestation.
As a zombie/horror movie, Dawn of the Dead is a top-tier production. I recommend it to any horror fans, especially those who--like me--enjoy a good zombie movie.