I see upscaling as soon to be dead, not only as a standalone but even in high end receivers. It's easier and cheaper to upgrade your sources, which are converging to HD anyway. What would you use them for? Incremental improvement from 720p or 1080i to 1080p? Most displays have embedded scalers that can do that pretty well, and they're getting better.
Hmmm, $700 scaler for my DVD player so it looks as good as BD at best, or $300 BD player? Hard choice...