His is a three day rolling poll. The poll today only included 2/3 of people that heard the presidents speach.
If you have premium membership they have a article explaining the Newsweek poll. I guess they disagree with it.
The do have Bush leading now in 16 battleground states.
The Newsweak poll is unreliable, except for how it shows trends. It had Kerry leading Bush by seven points before the Democratic convention, and leading by seven points after the convention (i.e. no bounce). So, at most, the Newsweak poll shows that Bush got a significant bounce from the convention, and Kerry did not -- a result in line with most other polls to date. I wouldn't rely on the Newsweak poll for anything else.
Also, the Newsweak poll arguably contained too many Republicans relative to Democrats and Independents, although the reason may be that more people are willing to identify themselves as Republicans today than they were several weeks or months ago. Someone else mentioned that Newsweak doesn't weight their polls by party affiliation, so the question becomes just how random the polling was and how good or bad a job it did identifying likely voters. Going by past experience, don't bet the ranch that they did a good job.