For many years now I have been very disappointed by stagnation, and down-right reversal in DPI trends. 13 years ago I was running a 19" CRT at 2048x1536, now to find a computer display with similar DPI is very difficult; to find a CRT is even more so, despite the venerable technology's superiority in virtually all image quality metrics.
TVs continue to get larger and larger, while 1080p is likely to remain the standard by which they are all measured for several years to come, and penetration of media with a native resolution > 1080 will take even longer. So there is little incentive for mass produced panels (e.g. TVs, and even computer monitors) to improve on DPI; I am glad however, that the emerging mobile device market is not shackling itself to the same philosophy.
Viva la DPI!