I've written birth plans two previous times and will again, although I think it's less common in Germany...
First time it went out the window as I was inducded 11 days late. Second time, the MWs really read it - it was things like I wanted skin to skin asap after birth, DH to cut the cord. Time on our own with the baby right after delivery (assuming everything was OK). They really respected it. The other things were like preference for various drugs, and also a big one for me that if I needed surgery i wanted stitches not staples... I've never written one WITH a mw though. I think it probably depends on how the care system works for you where you are - i know here that the MW who delivers our baby will be the one I've seen throughout (barring some horrible unforseen circumstances) so she should have a good idea of what I will and won't consider anyway - I found it useful in the UK, as I knew it would be MWs I'd not met before attending the delivery, so it meant that they could see what I hoped for and what options I'd be open to

I think even if you don't refer to it at all during labour it can be a useful experience to write one beforehand, just so that in your head you are aware of the various things that might happen and what the consequences are etc. There are a few online tick sheet ones - I've been looking at those in German so far (and having to use google to translate most of it) as I'm not sure about so much of the birth culture here - ie no pain relief other than epidural! So it's been good for me to see what sort of things they have included!
Ljayne, sounds good to be moved. No idea about iron transfusion, but I've had a drip before and it was fine, canular in hand and nothing else you'd notice... hope it makes you feel much better anyway!
Jessy, your pram sounds lovely! We haven't decided a name yet, but we have a shortlist of about 6 I think...! Most likely will only decide very late in the day if the last two times are anything to go by!
Taz, before I got pregnant, I hadn't even thought about labour or delivery, it was all about getting the baby in there! You're very organised!
Lyndsay, I'd look at some online birthplans before your MW comes, so you have some ideas, but I think it's pretty cool she's going to write it with you

Is that the MW that will deliver your baby?
As for me, I saw my other MW last night - she's a specialist in SPD pain, so I had a lovely hour on her couch... She's taped my bump too, which is really weird, but should hopefully provide some support. She said she though the pain coming back could coincide with baby going head down, so I guess it's a small price to pay to have the baby the right way round! She's on holiday now til the day before I'm due, so hopefully the pain settles now!!