Oh, how fun! Until I learned that I'd be having a boy, I was browsing the Lilly Pulitzer website for nursery fabric ideas. Oh well!
If I had one piece of advice to give, it would be to choose something that can transition to a toddler room or older. I'm really glad that we went with bright blues and red with a lot of sporty items and plaid, because now that he's 3 we don't have to re-do the room, and won't need to for a while. It's not too baby-ish. (My brother in law and his wife are having a boy, and they have a sage green nursery with an alphabet border -- but then again they didn't ask me!)
Had I been able to buy pink, this would have been my pick:
