It seems the prices have dropped enough for Blu Ray drives and disks to make the switch. A lot of prebuilt Desktops and Laptops seem to have Blu Ray by default or having a simple $50-$100 price up option to use it.
Interal Blu Rays are about $40 minimum currently and External Blu Ray is about $40. By next year these prices should be about $10 cheaper and with places like NewEgg and Amazon you could probably get one on sale before it.
The retail PC market isn't dead yet since it took about 2011 for digital sales to surpass and basically Digital distribution makes up half of the PC market. Every major game/ games ranging over $40 seem to have a retail version and it's interesting seeing even some indie titles trying to get retail versions.
I did think up somethings that can get in the way of this like adoption rates, it's pretty well known that people hate change and/or refuse anything different, many of the "DVD forever" gang will probably cling to DVDs till they're pretty much dead. Seeing as how all the next gen consoles will be using Slot Loading Blu Ray drives which cost a lot more than fat ones that would, this would probably take a while for the price to drop especially for small form factors PCs. However they could always use an external Blu Ray Drive.
However with those a lot of the cheap ones use USB 2.0 which may limit transfering speed, the ones that use usb 3.0 cost about $60 but that's still cheaper than using a slot loading Blu Ray drive. The price for games may go up a bit but nowhere near consoles since PC gaming doesn't have as many licensing fees as the consoles. Which is why not only Digital Distrubtion but PC retail can be cheaper than console versions of games.
The benefits of Blu Ray in PC gaming I see are since the typical PC game doesn't demand that much HDD space to use up the entire disc, the Blu Ray can be used to optionally play the game directly off the disk for those too impatient to install, and it will give decision to buy a retail copy some use. Although the HDD space required for games is increasing so Blu Ray could future proof itself for quite some time.