People like to buy stuff for babies. It's definitely possible to put together an AP-friendly registry that mainstream people can do their normal thing with, thus satisfying their desire to shop for you and take care of the things you actually need, rather than say "we don't need anything" and end up with a bunch of light-up plastic toys when they buy for you anyhow. :)
First off, I'd recommend putting a list together on Amazon... not only is it the cheapest place to get most big necessary stuff, but you can also use it as a universal registry and add stuff from your favorite Etsy shop or cloth diaper store.
As for necessary stuff.... for me, it consists of:
-a highly-rated carseat (suitable for my car, and I skip the bucket seat... my girls hated it)
-breast pump (I work at home, but need to pump sometimes and I am SOOOOO prone to clogged ducts it's ridiculous) and collection bags
-nursing bras (since it's your first, I'd suggest something like a Bravado Bliss or Bravado Body Silk so you don't have to know your exact size to fit it. You will probably go up in cup size and down in band size shortly after birth, but you can probably figure out basically what size you'll need since their ranges are wide. Get at least one bra to wear while you're waiting for your size to even out those first couple of weeks.)
-cloth diapers (go ahead and ask for all sizes NB-M if you know what you'll use, or for a variety of styles in NB/S if you don't. They can be pricey, especially if you don't end up liking prefolds, so might as well have others buy them) plus accessories... cloth diaper safe rash cream, pins and/or snappis, wet bags.
-Lansinoh lanolin or natural nipple butter
-nursing pads... I like nice cloth ones and find disposable ones uncomfortable. Etsy's a good place to get them!
-something to swaddle with (I've heard good things about wombies, but haven't used them. I like huge swaddling blankets a lot)
-somewhere for baby to sleep... cosleeper or bassinet for us since our bed is too small for full-time bedsharing
-simple, comfortable clothes--sleepers, nightgowns, onesies, cotton pants, socks, no-scratch mittens, t-shirts... you'll get cutesie outfits, no doubt, but most of the time you'll want your baby comfortable and easy to change!
-ring sling for first few months, 2-shoulder support carrier for later. This is my personal preference. I used mei-tais before, but I'm going to try a soft structure carrier this time for when I want to go faster.
For not-necessary stuff, but I like having it:
-swing--there were plenty of times my girls would sleep no other way.
-high chair, travel seat or something like that
-feeding stuff for when she's starting solids... bibs, utensils, cups, bowls, etc The good non-toxic stuff is pricey, so also good to plug onto a registry. She'll be using it before you know it.
She'll grow fast, so think ahead to what you'll need when she's crawling, teething, walking, starting explore outside, getting cold next winter, etc.