No, no, no, no, no! This is a terrible idea, and will end up causing you a massive headache in the long-run. If I see commented-out code like this, I will delete it because that's what version control is for.
If you really need to turn code on/off in different environments, you should be using feature flags: http://code.flickr.net/2009/12/02/flipping-out/ and at the very least you should be detecting the environment:
if (ENV == 'dev')
testStuff();
else
productionStuff();