My guess: It ain't gonna happen (a price drop).
The pricing is based, essentially, on what you would buy otherwise for the total functionality. The iPhone is a smart phone (very smart), an 8 GB video iPod, the best mobile internet device you can buy. What's the value of those individual pieces? Are the prices on those coming down any time soon? I don't think so. Did Apple ever drop the prices of iPods? They came out with smaller iPods and bigger iPods and improved iPods. They grew that category without ever dropping their prices (as far as I know).
Personally, I think Apple can and will meet all their sales projections with full priced product. If you're waiting for the price to drop before buying, I think you're going to be waiting a very very long time.