No. It will look like an SD picture, no better and no worse.
It has to be upconverted somewhere, either in the DVR or in the TV itself, to the TV's native resolution. What isn't happening is interprelating the undefined pixels between a 480i picture and 1080p picture. It's just lighting more pixels to fill in the blanks, but not re-creating what is missing.
It's like the old, "three points define a curve" rule I learned in high school drafting. If you had three points and you wanted to connect them, you got out your curve and lined it up on the three points, tracing a nice round path between the three points. That's what the best up-converting DVD players do. They add in information. With your DVR, it is simply drawing straight lines between the three points. Jagged, if you will.
Every HD display is upconverting. Say you have an LCD TV with a native resolution of 1080p. It has to convert the incoming picture, be it an SD picture at 480i, or a regular DVD at 540p, or an ABC HD broadcast at 720p, or even HBO HD at 1080i, to 1080p to display it on the screen. It's just doing it the simpliest way it can.
With your DVR, you're simply doing it inside the DVR instead of inside the TV.
Upconverting is not a be all and end all.
Have you heard of Faroudja? They are an company that makes upscalers that are smarter, adding in information to make the jagged lines into curves, to use my way-oversimplistic analogy above. The best upconverting DVD players use Fraoudja, or other similar intelligent upscaling technology, to improve the picture somewhat, although it will never get to real HD. Neither Dish or DirecTV DVRs or most TVs for that matter, use this kind of technology. It costs money and most companies don't want to pay the licensing fees.
When upthread I said DirecTV is more technically sophisticated than Dish, this is one of those places. A DirecTV DVR has an option called native pass-through. Whatever is the native resolution and screen format of the original picture, it will put that out. A 4:3 picture that's at 480i, which is analog TV and most SD satellite broadcasts, that's what it puts out. A basic off-the-air digital picture, which is 4:3 and 480p, it will pass that through, too. Same thing with HDTV pictures, with an aspect ratio of 16:9 and resolutions of 720p or 1080i. Those will also be passed through unchanged. If you have a smart upscaler later down the stream, and some expensive home theater receivers and televisions do (look for one with DCDi by Faroudja), it will upscale those various different formats to whatever the native resolution of your TV is, which, if you have expensive gear like this, is probably 1080p. You'll get a better picture. A Dish DVR can't do this. It will only output one resolution. It doesn't have native pass-through.
This is all real inside baseball, though, Maestro. We are quickly going to all HDTV. I wouldn't worry about this too much. SD television is SD television, which means it's yesterday's technology. I wouldn't spend too much time or money sweating it.