4K will come to blueray. they can do 4 layer disks. 100gb is enough for about 4 hours of 4K if I remember correctly. ( depends on compression.) 3d may go away again.
It's "Blu-ray". The limit for a Blu-ray disc has been shown to be 20 layers, so capacity shouldn't be an issue. Bit rate might be, there's no point going up to 4K if you are reducing the quality of the picture in other respects. The 40 Mbps bitrate of Blu-ray gives really nice motion so it would be a shame to compromise motion to get higher resolution. For 4K to keep the same motion quality, they'd have to up the bitrate to 160 Mbps.
It's amazing what some people consider to be adequate HD. Netflix attach the label to a 1 Mbps stream...we have 50 Mbps cable at home but what Netflix laughably calls Super HD isn't a patch on Blu-ray.
Picture quality 101 : The elements of a quality picture are :
Contrast / brightness (the darkest level vs. the brightest one)
Resolution (both static, and during movement)
Clearly calling something 1080P only considers one aspect of the picture (pun intended).
Right now the best picture available comes from Blu-ray, and this will be the case for a long time to come. Partner it with a large plasma TV, and the experience is just like going to the movies.
There's a Redbox near the marina and they have Blu-rays for $1.49