Reopening a question nullifies all pending delete votes on that question, and that seems to always have been the case (though I too thought it didn't).

Otherwise, delete votes are (currently at least) permanent, they cannot be retracted, nor do they age away. That may change in the future, as

Personally, I still think the delete workflow needs some work - bookmarking this for future reference. Shog9♦ Feb 25 '13 at 18:12

But that's not a high-priority issue, so it will take at least 6-8 weeks before it is tackled.

Reopening a question nullifies all pending delete votes on that question, and that seems to always have been the case (though I too thought it didn't).

Otherwise, delete votes are (currently at least) permanent, they cannot be retracted, nor do they age away. That may change in the future, as

Personally, I still think the delete workflow needs some work - bookmarking this for future reference. Shog9♦ Feb 25 '13 at 18:12

But that's not a high-priority issue, so it will take at least 6-8 weeks before it is tackled.