Two notes on these:
1. On the first one, note also numbers 11 and 12 Scott mentions in the comments.
2. The second is not always so specific to P vs. NP (and indeed has some overlap with the first -- #1 on the second list is a stricter version of #3 from the first). #3 and #4 for instance could be applied to lots of hard open problems, #6 to really any hard open problem, and #5 is basically fully general.
One for general mathematical proofs: http://www.scottaaronson.com/blog/?p=304
One specific to P != NP: http://www.scottaaronson.com/blog/?p=458