A while ago I wrote briefly on why the Singularity might not be near and my estimates badly off. I saw it linked the other day, and realized that pessimism seemed to be trendy lately, which meant I ought to work on why one might be optimistic instead: http://www.gwern.net/Mistakes#counter-point
(Summary: long-sought AI goals have been recently achieved, global economic growth & political stability continues, and some resource crunches have turned into surpluses - all contrary to long-standing pessimistic forecasts.)
I agree this 43k improvement is not representative of algorithms research in general (sorting is not 43k faster than in the 1960s, for example), but let's not call it 'very narrow': linear programming optimization (and operations research in general) is important and used all over the place in numerous applications in every industry. We owe a good deal of our present wealth to operations research and linear programming.
There have been great improvements in linear programming overall, but the paper talked about applications to many areas, and Kurzweil cited the one with the greatest realized speedup, which was substantially unrepresentative.
This has more numbers.