In reality of course CD's are already obsolete but, as was the case with vinyl, they will never truely disappear altogether.
The sad thing is that the replacement will not be as good a quality - even though that is quite possible because the majority of the music buying public simply do not care.
MP3 and its multiplicity of variants, loseless or otherwise, are the standard now - some better than others quality wise. There are already "audiophile" products that allow streaming over bluetooth from any mobile device that supports it. These will get worse in quality but much cheaper. Within a couple of years you will have mobile phones with 60 plus GB of storage for media (plus camera's and all the rest of the gadgets) that will in effect be entire entertainment systems in the palm of your hand. Once you can fit all of your media onto a single portable device that will become the standard almost by default.
Apple's Iphone is leading the way here but there are many others now coming to the market.
Fully agree with Who on his post - the music industry needs to get its act together here to stop the pirates from taking the new frontier on their own.
Note : Everything I believe today I will contradict tomorrow. (System in profile)