I don't own a PS3 myself, but I'm fairly certain you can set it to output 1080i for most everything. I believe there was an issue where some of the early games would not scale to 1080i, and there was quite a bit of people who weren't happy about it, and so it was fixed with an update. Since then, I'm also fairly sure that there have been other updates addressing scaling and output, so by now, I think it should be pretty good overall. The only thing that probably won't do 1080i is DVDs but thats because you don't have HDMI.
One of the things that I was happy about on my TV is that it does support 720p/1080i and basically everything other than 1080p. There were quite a few CRTs that would only do 1080i/480p (where they would actually convert it to 540p). I found out that mine even has 800 lines of vertical resolution. I haven't done any real testing, but it does seem to me that 1080i does show more detail on it (based on the football games I've watched), although I can't be certain, as I haven't done an apples to apples comparison yet. I'm waiting for the HDMI cable I got from monoprice to test that with the 360 that I have. I'm curious if I'll see much difference between HDMI and component, and subsuquently 720p/1080i.