Richard A. L. Jones, author of Soft Machines: nanotechnology and life is documenting a debate about the feasibility of mechanosynthesis between Philip Moriarty, a nanoscientist from Nottingham University, Chris Phoenix, Robert Freitas with some comments by Hal Finney. There may have even been some comments by Eric Drexler though he appears to requested those not be included in the documented exchanges.
The debate with archived discussions and current comments is here.
