DD, coming up to 4, is going through a stage of wanting to be bf to sleep. There have been periods when she's been happy to wave good night after her bedtime feed and for me to leave her awake - and with no tears or tribuilations, to go off to sleep on her own.
Talking to friends with DCs of similar ages, tend to think this up and down pattern of nodding off alone, and then needing more attention to get off to sleep is pretty common. Just thought I'd mention that, as because I am the only bf-ing mother of a nearly 4 year old I know, sometimes I fall into the trap of thinking it is the bf-ing that is the issue - where as in reality all parents have simliar challenges.
As SPB says, we also have an alternative routine - she will lie now and try and get to sleep as long as Mummy stays with her. I used to bring a magazine and sit on my glider, but lately I tend to bring the lap top.. I'm firm that she has to lie down quietly, and she usually nods off in 10 minutes or so.
I find the main issue for me is that it is so easy to bf her to sleep (assuming she is tired and ready to go).. So I think sometimes I feed her for longer than I'm happy with it, in the hope that she will nod off. If she doesnt' - and I then have to negotiate into the alternative routine, go get the lap top etc. - I can end up feeling a bit stressed, esp when I'm exhausted too.
I sympathise with the night wakings. Sleep (or rather lack of) has always been the main bugbear with regard to parenting DD (who is charming and easy in most other ways). I wuld generally always feed her back to sleep if she woke. It is only recently taht I have tried the Mummy is too tired line (say when she was 3 1/2 years) and she has accepted that pretty much without protest - not sure if that is becasue of her age though.