Here are your "big dialogue" American writers, Mr. Engdahl (and commentators who focus on the Roth/Updike canon) -- non-parochial, experimental, resonant, collaborative, political, lyrical, outspoken. And tech-savvy: embedded and downloadable MP3s available for all the poems, and videos for some.
And, from the UK, 42 writers campaigning against the government's planned 42-day pre-charge detention, as part of Liberty's "Charge or Release" campaign. Organisers Hari Kunzru, Simon Prosser and Anya Serota comment:
It is a measure of the unpopularity of the proposed legislation that not a single writer declined to contribute on the grounds that they in fact supported it. Whereas 42 of the best novelists, essayists, memoirists, poets and journalists around sent us the uniquely powerful contributions you will read on this site.