Karl is fond of sharing the story from his days as editor of Computer Weekly. They had a guest editor for one issue, who sat in on various editorial conferences, an eye-opening experience for him. Much of the material in those discussions never made it into the magazine - and that seemed like a loss to him.
I've long wanted to see us do a real "behind the scenes" blog, sharing the though-processes behind the creation of an issue with the readers - and involving them in that process. Arena does exactly that for a very specific section of the FT, and does it pretty well. At the moment comments on posts vary between around 20 down to none. But it's an interesting experiment, and I wonder how long it will before other titles follow suit.
Our community editor's blog did get a reasonable response (relative to its audience) when she invited comments on a particular front cover and on a controversial score in our Mystery Shopper feature. But it's post-analysis stuff, not nearly as gutsy as bringing readers into the decision-making process.
Only one reservation on Arena after briefly scanning it - it probably reads fine if you're following it every day, but the mechanics (comments reposted as entries, with more comments appearing on the new entries, if I understand it right?) make it difficult to parse if you come in later in the debate. And none of the posts are categorised or tagged, so that's only going to get worse as time goes on. Maybe good archiving isn't really the point though...
Yes, it certainly seems built for a regular and loyal audience, which means it will take a while to build up a decent readership - but maybe that's the point?
It will certainly keep the quality of commenting higher.