I agree, BRU does a great job of registry starter. Here's my list of things that weren't basic necessities but sure came in handy!!
Stroller/car seat combo (travel system) - it was great being able to drop the car seat on the stroller and not wake a sleeping baby when I wanted to go shopping or for a walk. Couple pieces of advice regarding strollers: make sure you can lift it and fold it quickly and if you are planning to have more than one child and think you will need a double stroller down the line, make sure your seat will work with a double stroller that you like.
Baby Bjorn/Sling - basically some sort of on body carrier. I wouldn't say I'm a baby-wearer per se but it sure was nice to be able to be moble and use both of my hands. My SIL was so good at using her sling she was able to nurse while walking around shopping at Nordstrom without anyone being any the wiser. I preferred the Baby Bjorn carrier over the sling - it is all a matter of personal preference and what you want to use it for.
Bouncy seat with vibrations - I can't tell you how many naps Liam took in this early on. It was great when trying to get a meal on the table.
If you are planning to BF you probably don't need to purchase any formula. The hospital and formula companies seem to do a good job of providing samples that can be used in a pinch. I'm not sure what to do if you are planning to do formula (We exclusivelyBF) but I wouldn't suggest buying a lot of before the baby comes just because the baby may need a different brand or type (and it does expire). I think the hospitals are pretty liberal in giving out samples that get you through the first couple of days at home.
Same thing goes for diapers - I wouldn't buy more than one or two packs of newborn or size 1 diapers. If you have a baby as big as mine, they'll be out of the newborn size diapers before they come home from the hospital. 
I'm so excited for you! Becoming a mother has been the most rewarding (and draining) experience of my life!!
: ) lori