The Wall Street Journal iPhone App (iTunes link) just hit the iTunes Store. We've downloaded and are looking through it as we type. It isn't full of content yet but we're sure more will stream in as time goes on. Even though the video section only has six videos, we were able to Walt Mossberg's MobileMe re-review.
While we generally like the NYTimes content better, the WSJ.app does a lot of things better than their iPhone app (which came out almost a year ago). The 'photo flipping' of articles is great and the video works really well as well. A very positive, polished first experience.
If you are a fan of the Journal, this app will make a great addition to your reading collection. (and the articles are free!)