When I was at the Weird Science meeting, where I live blogged the four talks, I discussed live blogging with Tom Morris. It was his view (and I am sure others) that live blogging is over, now everyone can video talks and post them on youtube, other websites or even on your own blog. In the past this did not happen and only some live blog records remain of some important and valued meetings.
I understand his point but am not sure that it is over. My thought is that the problem with videos is that there is no searchable index of terms to find the talk. Now there might be reviews but they would not methodically cover all relevant terms - only some that might be relevant to the reviewer. When someone posts a video they can of course add tags or labels but how many and who decides which ones? Again this might be biased by the interests and knowledge of the poster, as well limited by their time.
So surely live blogging when videos are available shortly afterwards (hint, hint, CFI London), is still useful, as a means to finding those videos, to finding talks, themes and speakers of interest?