Yeah, for me it's just movies that aren't available on Blu-ray (or things like concerts that likely will never come out on Blu), but have been broadcast on HD cable... Even if it's not blu-ray quality, it's still better than DVD (although sometimes you have to deal with an obnoxicon in the corner...
) If the Blu-ray ever gets released, I just buy that as it's pretty much always a better looking picture.
I usually transcode the 1080i ones to remove the pull-down to make them 1080p, but even then I use settings that aren't strictly blu-ray compliant to help preserve the picture quality as much as possible...