You might be interested in this article [1]. Basically, even if many proofs are incorrect, their results are almost always still true. Also, there have been many large changes in what counts as 'rigorous' over time. I agree with you that computer-checked proofs seem like a logical next step in the rigor of mathematics.

[1] http://www.gwern.net/The%20Existential%20Risk%20of%20Mathema...