I prefer Total Biscuit's analysis.
I still preorder though. But I do have some restrictions. First, I don't preorder games sight-unseen. That's just silly. Further, the games I preorder are largely imports, and frequently lesser known/lesser promoted titles.
Why is this important? Well, it's worth noting that originally preorders were something done to benefit customers. They were a way to ensure that you would be able to get a game that a store otherwise might not get in quickly, or even at all.
I can't recall the number of times preordering has gotten me a game that otherwise would never have come into a store, or that store employees didn't know about.
So, yeah, I've preordered Rune Factory 4. The rest of the series was brilliant, the videos I've seen of it look great, and it has gotten phenomenal reviews in Japan. And the game is not a triple-A title. There are a lot of people who still don't know of the Rune Factory series, and it's not the sort of game that a small store will typically get in immediately.
I'd also preorder a game to show my support of it. I'd preorder Final Fantasy Type-0 as soon as a translation was announced, just so that Square would realize that there is a dedicated fanbase for that sort of game.