Exactly, which is why whenever someone asks me what pedals to get, I ask if they've decided on what style of shoes they want to wear.

I've got some Sidi MTB shoes like the ones in the last pic of that post, and they feel a lot like a pair of Sidi road shoes I've got -- stiff, no hot spots, fairly light. But, they're easier to walk on when I'm off the bike, and the pedals they use can also work with all the other shoes I pictured.

I've got road shoes for the fancy road bike when I take it long distances and ride like I'm a slow-domestique-in-training. I don't need a whole lot of versatility on that bike. For my commuter, and especially since I've converted it to drops, I'd like to use a variety of shoes, maybe even some sandals for the summer, while riding to work or across state lines. So, it's going to have a different clipless system than the road bike.

The shoes determine the pedals, not the other way around. IMO.