The logical solution isn't to ignore or remove the karma system, but to use it better.

For example, with sufficient data to analyse, it shouldn't be tremendously difficult to find relationships between users who tend to agree or disagree, and provide each user with a customised view, taking these preferences into account.

(Of course, slashdot took a slant at making it cleverer - by allowing upvoting for different reasons - e.g. funny vs. insightful.)