What is difference between a upconverting 1080p DVD HDMI player and a blu-ray?

I'm sickened by this whole blu-ray / HD-DVD war. I know there are some DVD players that have both formats but why should I spend that much money on a new player and new movies when I can simply buy a Upconverting DVD 1080p player with HDMI? I guess my question is will the quality of the unpconvert be as good as the Blu-ray/ HD-DVD versions?

Related posts:

1. What are the best home theater system for a 1080p HDTV and blu-ray DVD player?
2. Is there a noticable difference in using a 1.1 HDMI cable versus a 1.3 HDMI cable on a Blu-Ray dvd player?
3. How do I connect Blu-ray DVD player and TV to my new HDMI Sony entertainment system?
4. what is hdmi cable and do I need it to make a blu ray DVD player work?
5. do you need an hdmi output in home theater system?