Michael - nice setup! I actually just discovered Aperion within the last week, and I cannot wait to get my hands (and ears) on their speakers. One question I don't think has been asked yet...how does it sound? Your setup is pretty similar to what I've been considering. I'm looking to get the 532 center and front speakers and maybe the 4 series surrounds. What kind of power can you get from these speakers?
In regards to your TV, good choice! I just bought a Panasonic TH-42PZ77U 1080p plasma, and I'm thrilled with it so far. No problems with burn in yet. In response to standard definition leaving bars on the side of the screen, I have not experienced this. I have DirecTV (no hi-def yet), and the picture always fills the screen to the sides. Sometimes there are bars on the top and bottom, but I believe this is from the programming. My TV has a setting to show the picture in 4:3, but I never do this. I also do not have to use the Zoom feature on the TV to fill the screen, it just fills it automatically, which is fine by me. I also never use the H-Fill or any other aspect that stretches, because it distorts the true image too much.
I was very torn in regards to what type of TV to buy. I was leary of plasma, because I've seen burn-in first hand, but the TV in question was constantly in a 4:3 mode, and it left vertical bars on both sides. I'll never do this to my TV. I was also leary of LCD because of motion lag, and the "refresh rate battle" seems to never end. Although 120Hz is the "fastest" right now, I've already heard talks of 180Hz. Lack of burn-in is a plus, though. I think rear projection TVs are better than ever, but we have a small room (<10ft. viewing distance), and the majority of them are too big (at least according to my wife!)
So, I chose plasma for the ability to handle fast motion, it's deep blacks, and it's great viewing angle (we have seating somewhat off to the sides). I'm not going to say plasma is best, it was just best for my situation. I think all HDTVs have great things to offer, and I'll never ridicule somebody for their choice, because it works for them. I don't view much programming with constant static images (except annoying network logos), so burn-in wasn't a huge concern for me, although I'll try my best to prevent it.
Again, nice job on your setup. I hope you get a lot of enjoyment out of it.