Assuming it's a newer digital 1080p display, then yes it scales everything to it's native 1080p resolution. This scaling may or may not be of high quality, so there may be benefits to using external scaling instead of the scaling provided by the display.
It will scale everything to 1080p. I have no idea whether it will do it well or poorly. So no, the benefits of external scaling are not moot, but yes you will be getting 1080p on everything. You may not 'need' to have any kind of scaling to get 1080p, but you may want one to get 1080p that looks as good as it could.
I just bought a 61 inch samsung 1080p. I am using a panny rp82 for my DVD watching. It has a max output of 480p. If I use 480p or 480i, my TV automatically displays 1080p anyways, so does it matter if I select 480p on the DVD player? I turned it off, and for some reason, DVD's look a little better, but I dont want to be missing something by not having 480p.
I'm getting a Denon 2807 AVR. I noted the receiver has the ability to upscale the input video signals to an 1080p output via HDMI. I intend for the video output to be HDMI to my HDMI input on my TV (1080p).
I have an older DVD player with both component and s-video outputs.
The question this raises for me is whether or not it matters which video output I choose from the DVD since the signal will be converted to 1080p.
Would there be any benefit of using component video out of the DVD player vs. s-video out if the Denon is capable of converting the signal to HDMI?
The DVD should be deinterlaced before it's scaled. So, if you send your display 480p, that means the player deinterlaces it -- the display then scales it. If you send your display 480i, the display will deinterlace it to 480p then scale it. It just comes down to which does a better job of deinterlacing - your player or display. The HQV Benchmark Test disc may be worth picking to do some objective comparisons.