Is it worth upgrading DVD to progressive scan?

I just purchased an HDTV with the ability to play progressive scan (480p). I currently own a Yamaha regular DVD player. Is progressive scan really worth upgrading to or should I wait on HDDVD?

You will be waiting for 2 years then...go ahead with a progressive scan player...
YES - progressive scan is worth it and you are not getting the benefit of the TV without it.
Don't wait, get something now and if you need to, sell it and upgrade later.
You can pickup a Sony 9000ES for around 800 bucks now.
If your set has a really good line doubler then there is only a slight difference going to progressive. I'd say the image is more film-like. I use the Panasonic RP91 with progressive feeding my Pioneer Elite. The Pioneer has a very good doubler so the difference is slight but it is better using the DVD player in progressive mode. It's close though. Hope this helps.
I could see a noticeable difference between my sony 7700/xbr200 and my friend's sony 9000/xbr400. The images seemed more solid and three dimensional. Not enough for me to upgrade though. The 7700 has a HUGE advantage over the 9000 in that it plays all of the vcd (video cd) formats.

My computer w/ Sony gdm-fw900 24" flat crt beats both of these.

"Is it worth upgrading to a progressive scan DVD player"??

In a nutshell......... YES!!!!!!! In fact, if you have a 16:9 HDTV Widescreen Television, you can get a good progressive scan player for peanuts right now. You can get either a used Pioneer Elite DV-37 for about $400.00 to about $450.00, or you can get a used Sony DVP-S9000ES for about $700.00. Right now, you cannot go wrong with these two players. Either of these two players ought to serve you well until the new HD DVD Players hit the market in about two years or so. Until that happens, these two ought to do until then.

Good Luck.........

Toshiba progressive scan works great 189.00 cant go wrong.
I use a Yamaha 920 with Faroudja DCDi technology. Oh my!
All the difference in the world! Best upgrade for $500.00
I have ever found
Depends on the quality of the doubler in your HDTV. Test your TV with a progressive scan DVD player, borrow one, and A/B through the component TV inputs to 480P input and your regular non-progressive component inputs. With my Sony the progressive scan is better but it's not spectacularly better. I remember switching back & forth on the DVD movie The Mummy. The flickering torches had a more 3 D flickering quality in non-progressive but the picure had a slight more film like look in progressive. But it was close.