My rule of thumb is this: Is the event something that has some bearing on my current life?
So I think people should definitely disclose early on their current marital status if they are still legally married, separated, or very freshly divorced. They should also disclose within the first few dates whether they have children, a stalker ex, mental or physical issues. I'd probably throw any major fiscal things into that mix, like being currently unemployed or different living situation.
My background is very similar to Alice's, so I don't bring up the divorce (especially since it was disclosed on my dating profile), but I would mention it in passing at some point. (e.g. Oh yeah, I've been to X island - that was where ex-DH and I were married). I don't think it's ever gone more than a few weeks without being discussed.
At some point it feels a bit odd that it hasn't come up and if I were the guy I'd wonder if she'd kept it from me for a reason. But if they were straightforward in other aspects, I'd let it slide.