I think it depends a lot on weight, adjusted age, and your pedi's opinion. I've heard of moms on here who did it at 12 months actual but our pedi insisted we wait until her adjusted birthday...
I have one son who is allergic to milk (read anapylactic *sp?* reaction, not lactose intolerant with loose stools and vomitting) so I will not even try milk until 12 months adjusted and nothing with milk in it including whey, yogurt, etc.
We transitioned at 12 months actual, after DS's pedi appointment. We also went cold turkey. But I later found out that it wasn't so much cold turkey b/c our DCP had been giving him cornflakes/milk for a little while. Oh well!
I agree that it has a lot to do with where you're preemie is at at 12 months actual, espc in regards to solids. I waited until they were almost 8 months actual (5.5 adj) until I started solids, but they've been doing so well and have been really into them and tolerating them that I think I'll introduce cow's milk at 12 month actual. I'm still hoping to BF some then, too.
Re: Transitioning to Milk at 12 months actual?