Just to clarify the post above, this is not a MAP (minimum advertised price) policy. This is a UPP (unilateral pricing policy). The difference is that under MAPs, a retailer can use workarounds like "Add to Cart to see lower price" to offer discounts, whereas with UPPs they can't (well, they can, but the manufacturer will strong-arm them not to by threatening to cut their supply off). UPPs used to be considered illegal price fixing until a 2007 U.S. Supreme Court ruling changed that.
Quite a few manufacturers use UPPs now...Apple, Sony, Samsung, Nikon, Pentax, Canon, to name a few.
As to how they affect the industry, it's hard to say. The manufacturer may benefit indirectly from keeping the perceived value of its products up (no more promotions that might create an expectation for lower prices, like those sub-$3000 5D3 sales). B&M stores and smaller retailers benefit over larger stores like Amazon, B&H, etc. Consumers ultimately pay more because retailers are prohibited from competing against each other based on price. When an entire industry does it (I know this is the case for musical instruments, maybe smartphones) it almost creates an anti-competitive effect, because manufacturers can effectively collude with each other not to drop prices below minimum levels. That's how it seems the DSLR industry is shaping up to be.
