Yep, it's the same with all technology: cell phones, computers, now cars. Waiting will always yield something better. If you need a car, you can't wait. I suggest that once you buy something, you stop wondering if it was a good decision or not. Do your homework, choose what's best for your needs at the moment. If what you need is literally right around the corner, guaranteed, maybe you wait a few weeks. Otherwise, go for it but don't look back too much. Hindsight is 20/20 as they say. If you torture yourself with that, you'll never be happy.
This is not to say you should buy without doing your homework though