On the money, baby!
If you haven't seen it already, Francine Kopun's article on the economic impact of maternity leave is worth a read.
It is absolutely true that we can get easily caught up with purchasing stuff before baby arrives. And it gets a little ridiculous. Do we NEED a bum-wipe warmer? Probably our babies can do without. (Designer diaper bag, I'm not so sure... Come on, it's like your purse for a year!)
Now, I've decorated two nurseries in two different houses with rather a lot of enthusiasm (and not enough recognition of the fact both my children are boys). But I have always maintained that no baby is going to come home from the hospital and say, "OMG, I can't BELIEVE you didn't finish the quarter-round on my baseboards. WTF, I'm outta here." Remember that these people can only see 20 cms in front of their faces, for starters. The nursery is about us, our nesting instincts, and feeling like we're doing everything we can to anticipate what cannot be anticipated at all until you've brought a squawking helpless creature into your life, bewildered, slippery, and wanting desperately to get back inside.
"Babies are an inestimable blessing and bother." That's my favourite Mark Twain quote.
There are some great points being made in the comments. Check it out.