i know, i'm double posting the same stuff
I think it's important to note that there are different flavors of HD panels for sale and you have to be careful that you're comparing apples to apples and not just looking at specs.
True 1080p resolution on a plasma is 1920x1080. So while the screen size might be comparable between brands, unless you're comparing panels with the same resolution, you're comparing apples to organges.
The sub $1500 panels are usually 1080i or 720p, don't make a mistake.
I'm struggling with the purchase right now too, my 40" SONY WEGA HD (tube) is still working great so I can't justify the purchase, but i really would like the panny 58" 1080p but it's $3500 . If i'm spending > $2k on a TV, I'm expecting it to last for 5-7 years, and in that time i'm assuming that 1080p will be more ubiquitous, so buying a 1080i or 720p right now could be wasting money as i'll look to replace it in 2-3 years.
So bottom line is make sure you're checking the resolution so that you don't have to replace the panel in 2-3 years and waste money.