Here's a description of what they're doing. Zyvex is the best-funded group working towards molecular nanotechnology. There is good coverage of Zyvex at Next Big Future, including an interview with CEO Jim Von Ehr from May. Here's an answer I thought had interesting details:
Question 6: Eric Drexler has advocated a DNA origami approach, but others favor a direct to diamondoid strategy. Which approach do you favor?
Answer 6: We actually have our own distinct approach which is neither DNA origami nor direct to diamondoid. The ease of programming a computer controlled milling machine, which could make all manner of macro-scale products out of metal or plastic simply by changing the program, makes our paradigm compelling if we can build something similar at the nanoscale. The DNA approach doesn't lend itself to that flexibility very well. The diamondoid approach may be a great end point, but we simply don't have that capability now. We lack the precision and well defined tips to do diamondoid. By contrast, our approach gets us to rudimentary molecular manufacturing fairly quickly.
A recent presentation by John Randall (VP of Zyvex Labs) at AVS 2010 is available here. Jim Von Ehr predicts rudimentary molecular manufacturing by 2020.