If your wife is 5'5 or taller don't let her feel like she HAS to choose a women's specific bike. She might anyway, but she'll actually have more options.
If she's short (my wife is 5'2) she's going to be more limited in her choices but don't let her rush into one. Even if it requires some driving about, I'd really suggest trying a bunch of different brands unless she finds something right away that seems to be "the one."
My wife was just too excited to get a real road bike and got the first one and its....eh. She's happy with it, I'm not as for the price it was spec'd pretty crappily IMO.
Now if she'd just let me ride with her.

I keep telling her she won't hold me back at this point, but does she listen? Nooooo.
