There are 7 * 10^9 carbon atoms in E Coli [1], so we're probably a decade or two away from being able to do any kind of simulation at the atomic level.
Though it's probably getting close to the point where getting the right algorithms is the bottleneck; if you could somehow bring the techniques and optimizations we'll inevitably learn over the next 100 years back to today, a half decent simulation would probably already be possible on a cluster of commodity hardware.
Unless the techniques revolve around a new method of computation, of course - maybe memristor logic helps with that kind of thing.
Though it's probably getting close to the point where getting the right algorithms is the bottleneck; if you could somehow bring the techniques and optimizations we'll inevitably learn over the next 100 years back to today, a half decent simulation would probably already be possible on a cluster of commodity hardware.
Unless the techniques revolve around a new method of computation, of course - maybe memristor logic helps with that kind of thing.
[1] http://bionumbers.hms.harvard.edu/bionumber.aspx?s=y&id=...