I have had a Toshiba Upscaling DVD player for some time now with my 1080p TV. I have to say, they're well worth it as DVDs look so much clearer and sharper in high def upscaled than I've seen with any other kit, including my HTPC.
Recently got the Angels and Demons DVD and the quality when upscaled to 1080p was amazingly good for a DVD. Best I've ever seen.