Microsoft's half-price deal for Windows 7 ran out a few weeks ago, bumping prices back to painful levels. If you're thinking about pre-ordering anyway, wait. There's a decent chance there'll be some new deals as we get closer to launch.
They want the launch to be a success, after all, and success will be measured by sales numbers. The standard upgrade pricing—$120 for Home Premium—is too much to guarantee the kind of rocket launch Microsoft's looking for. You know, the one that shows they're back on track, especially after this past quarter.
Pressure from Snow Leopard's flat $29 upgrade price will help, and Microsoft's been savvy enough with press for Windows 7 they know that staging another set of deals will be a positive boost getting closer to launch. The early summer pre-orders were for the super-nerds—your dad probably didn't hear anything about it—so another round to get semi-regular people on board would be smart.
Plus, you know, we've heard some stuff. [Giz's Windows 7 Coverage]