One of the major reasons for concern from presenters and conference organisers about the notion of conference bloggers is that having unpublished work discussed online may violate the embargo policies of journals and damage their chances of publication.
At the same time, however, our cardinal rule has always been to promote scientific communication. We have therefore never sought to prevent scientists from presenting their work at conferences, or from depositing first drafts of submitted papers on preprint servers. So Nature journalists or those from any other publication should hear results presented at a meeting, or find them on a preprint server, the findings are fair game for coverage -- even if that coverage is ahead of the paper's publication. This is not considered a breaking of Nature's embargo. Nor is it a violation if scientists respond to journalists' queries in ensuring that the facts are correct -- so long as they don't actively promote media coverage.
Sounds good to me, and I hope to see similar clarification from other journals in the near future.
Personally, I think that the conditions under which scientists should go into secret society mode are rare and ephemeral. In those think sessions ... the weekly lab meeting, the get together at someone's room at a conference to brainstorm the grant you'all are writing, and so on .... these are conversations that should not be twittered. But a conference is a venue for open discussion in almost all cases. I don't understand the need to get up in front of a group of people at a conference and somehow know that some or much of what you say will be somehow private or not subject to being further discussed.
The strange situation that emerges when we contrast the rules of the press and the rules of bloggers is a temporary situation that will go away shortly and is of no consequence.
If there are scientists who have been speaking at conferences about things that should not be disseminated, they need to reassess what they are doing at these conferences.
Indeed, to push this along, I think all conferences should be live blogged.
I've not live blogged a conference, but the last two that I attended certainly got blogged as the conference was going on. In each case I sent the presenter a link to the blog post and in each case I got a thank you.
Nature generally seems pretty good about these things. They also have a forum on Nature Network called Ask the Nature Editor, so you can grill them on this and other things in detail.
Or just ask me right here.