Oh, cool -- I didn't know about the importlib benchmarks.  Thanks Brett.

Here are the results (OS X 10.7.4, Dual 1.7GHz Core i5, 4 GB RAM):

$ ./python.exe -m importlib.test.benchmark
Measuring imports/second over 1 second, best out of 3
Entire benchmark run should take about 33 seconds
Using <function __import__ at 0x1063bdd40> as __import__

sys.modules [ 41831 41812 40914 ] best is 41,831
Built-in module [ 20327 20441 19775 ] best is 20,441
Source writing bytecode: small [ 2108 2119 2117 ] best is 2,119
Source w/o bytecode: small [ 5093 5075 5106 ] best is 5,106
Source w/ bytecode: small [ 6021 5915 5997 ] best is 6,021
Source writing bytecode: tabnanny [ 379 379 379 ] best is 379
Source w/o bytecode: tabnanny [ 448 453 456 ] best is 456
Source w/ bytecode: tabnanny [ 2270 2279 2279 ] best is 2,279
Source writing bytecode: decimal [ 28 27 28 ] best is 28
Source w/o bytecode: decimal [ 30 30 30 ] best is 30
Source w/ bytecode: decimal [ 256 254 259 ] best is 259

$ ./python-with-sorting.exe -m importlib.test.benchmark
Measuring imports/second over 1 second, best out of 3
Entire benchmark run should take about 33 seconds
Using <function __import__ at 0x104b01d40> as __import__

sys.modules [ 42369 42203 42348 ] best is 42,369
Built-in module [ 17060 16358 20486 ] best is 20,486
Source writing bytecode: small [ 2118 2112 2127 ] best is 2,127
Source w/o bytecode: small [ 5121 5098 5125 ] best is 5,125
Source w/ bytecode: small [ 6015 5652 6046 ] best is 6,046
Source writing bytecode: tabnanny [ 367 368 366 ] best is 368
Source w/o bytecode: tabnanny [ 439 429 439 ] best is 439
Source w/ bytecode: tabnanny [ 2267 2274 2277 ] best is 2,277
Source writing bytecode: decimal [ 27 27 27 ] best is 27
Source w/o bytecode: decimal [ 28 28 28 ] best is 28
Source w/ bytecode: decimal [ 257 259 259 ] best is 259

Pretty similar results either way.