I was in the local Walmart over the weekend, and spied two LG 60PN5000 60" 1080p plasmas boxed and priced at $598. They're not displayed on the wall or anything...just in the center aisle with several other discounted TVs.
I don't think the price is anything new (I saw on Slickdeals that this same TV was available at $598 a year ago), but was surprised to see some plasma models still on the floor.