I would make any changes you want to make now, before the baby arrives. What changes they are are obviously up to you. If you want the dog upstairs, that's fine, if you want the dog on your bed, that's fine. I wouldn't have a dog and baby (or any child) sleeping in the same room though.
If your dog is very clingy and you want her to learn to spend time alone, put stairgates up and then get the dog used to spending short periods away from you, behind the gates, but give her a bone/stuffed kong so that she starts to see the 'alone time' as a good thing and open the stairgate again before she's finished, but then take the bone/kong away, so she learns these are special things she only gets when she's alone.
If the dog is well trained, she should simply leave the baby alone when you ask her, if she's not that well trained, then start on the training now. Also, it is very, very important to never leave the dog and baby alone even for a second, so a stairgate on the living room door to shut the dog out when you need to pop to the loo or leave the room (assuming baby will be in the living room that is!) is a good idea too.
If the dog is used to walks at regular times and you suspect this may have to be more flexible once baby arrives, start to adjust her routine a bit now so she gets used to the fact that walks/dinner/play time are when you say and not at set times.
Most of all, I would treat the dog very matter of factly when baby comes home, don't make too much of a big deal out of it. Giving the dog treats around baby is a good thing, as it will encourage the dog to associate the baby with good things and she'll start to think 'ooh, look what I get when this baby is around' or along those lines. 