Duplication of effort is a non-problem, and any attempt to "fix" it would reduce contributions and discourage innovation. With good metrics the best solutions will rise to the top over time.
I'd say every minuted wasted reinventing the wheel is a minute that was not spent solving interesting problems.
I'm not sure what you're referring to when you talk about fixes that would discourage innovation or contribution. I'd say I suggest the opposite, in fact :)
Duplication of effort leaves more room for experimentation, so it's not all bad.
If there was only one canonical version of all modules, it would be very limiting.
For problems that are deemed solved or community issues, having one or canonical module is great. A good example of this is JSLint and JSHint.
For problems that at TIMTOWTDI, duplication of effort allows exploration of the problem space. Once the right location for the new hive has been found we'll just headbutt the other worker bees into submission :P