I don't totally get why this is such a huge debate, other than the fact that it is poorly explained, in general, and poorly understood.
Drop the "i" vs. "p" as it doesn't matter with most modern displays. An interlaced picture is de-interlaced on most modern televisions, before it gets displayed. The difference is that in 1080i, you get a 540 line image 60 times per second (which get combined to become a 1080 line image that displays every 1/30th of a second, on modern displays). At 1080p, you get a 1080 line image the displays every 1/60th of a second. Effectively, you're looking at a 1080 line image on 1080i displays, but at a lower frame rate (30 fps) than 1080p (60 fps). That's the only difference.
So do you want 30 frames per second, or 60 frames per second? If bandwidth is no consideration, everyone would say 60. But if every 2nd frame is a repeat of the previous one, do you really care? Films are 24fps. That can't be upconverted unless you speed the film up. So the vast majoriy of Hollywood films don't look any better in 1080p than they do in 1080i.
Movies are 24fps, so the 1080i format has that covered when upconverted to 1080p. In fact, I think Blu-Ray being 1080p(60) is a marketing thing. How can a 1080 line, 24 fps image, look better when reproduced on a 1080 line 60 fps display, vs. a 1080 line 30 fps display?
Now, do you want more HD channels, or more frames per second on the ones you have?
What about this? (and the debate of 720p vs 1080i repeats)... do you want 1080 lines at 60 fps, or 2160 lines at 30 fps?
I think TVs will get bigger yet again, and the next era will bring higher resolutions, not higher frame rates, for most material.
My main thought here -- don't think of this in terms of your circa 1990 CRT computer monitor. Interlacing looks bad on CRT monitors, not LCD or Plasma panels, or even projection LCD/DLP/LCOS. These displays don't "fade" out and cause flicker. The debate is not "flicker" vs. "not flicker." It's frame rate.
1080i vs 1080p is a 30 fps vs. 60 fps debate. So which is more bang for the buck -- more pixels per frame, or more frames per second?
I think the requirements of 1080p, bandwidth-wise, would give birth to a new, lower frame rate, higher resolution format, and the debate will continue.