The Foresight Institute recently announced a new initiative with a stated goal of "making molecular nanotechnology (MNT) happen sooner rather than later." CRN agrees that a planned program for early development of the technology is probably a good idea for a variety of reasons.
Early development of molecular manufacturing capability increases some risks, but reduces others; overall, we think it's safest to develop as soon as possible. This is a preliminary conclusion, and we may change our opinion, but there are solid reasons for taking this position. The development of this new technology seems inevitable sooner or later. If development is delayed, it will rapidly become easier and cheaper, thus harder to control. Also, it's probably the case that early development will allow more time to develop nanotechnology-based protective technologies—which may be necessary to cope with some dangerous ramifications of the technology. Finally, if it's done right, molecular manufacturing could save millions of lives per year and greatly decrease the environmental damage we're already doing. The costs of delay are significant, and may even outweigh the risks of development.
That's an overview of our reasoning. Read a more detailed analysis here.