This is clearly one the biggest science news stories of the day/week/month/year/decade and there's tons o' hype...so i'm not going to do a lot of commenting until I have a little time to look at it. Not that i'm any sort of authority...but I like to go over things at least a little bit before trying to summarize and/or synthesize.
The actual Intergovernmental Project on Climate Change (IPCC) report can be obtained here today (2/2/07). The last report was in 2001...this is a significant body of work involving hundreds of scientists from around the world. The review process to decide on the final wording was quite rigorous.
The one thing I'd like to remind people is that this, the first report in a series, is the scientific background. The full report about policy is forthcoming (although there is a short summary of that too). It is extremely important to separate these. Yes, of course they are linked...I don't deny that. But, we should emphasize the objective information at this point.
There will be tons of noise about this report from every direction.....don't read mainstream media summaries that try to present "both sides"...and don't read your favorite op-ed columnist's pre-emptive commentary. Just read the dang report!
If you got to the end of this post and are lazy...here's another link to the IPCC website to download the report. Do it.
RealClimate, as usual, has a great post and good discussion going here.