The Guardian blog thing is probably a lost cause. A good blog develops a community of posters over time. These may include a fair number of troll and imbeciles, but even a passing aquaintance with each other, and some awareness of what has been discussed before, allows a measure of debate to take place, and a collective coping mecanism against trolls to develop. In the Newsblog you have essentialy a subset of the readers of a given news item shouting past each other and then disapearing back into the TCP/IP void.