I think it's difficult to get answers to this question as people will mean different things by "self-wean". A couple of PP's have said they didn't offer the breast but wouldn't have refused if LO asked, and counted that as self-weaning, but KellyMom describes "Don't offer, don't refuse" as a weaning technique. LLL and KellyMom say any refusal of the breast before 12 months is highly unlikely to be self-weaning, much more likely to be a nursing strike.
I expect my baby would be at the older end of the spectrum if we decide to self-wean, he's always been such a booby monster. I haven't decided yet but if he's still feeding at 3 I may try some gentle mother-led weaning techniques. I'm already coming under pressure to wean, especially from DH's family, but my lovely DH is doing a great job of telling them to keep their noses out

. I'm still really committed to BFing and I'd be devestated if he self-weaned any time soon. Night weaning on the other hand...