While the mainstream broadcasters are still figuring out how to provide 4K broadcasts it appears Netflix may in 2014 be offering 4K (3840 x 2160 pixels) resolution streams. The US based dslreports.com indicates that this ultra HD stream would run at around 15 Mbps.
Only recently Netflix added super HD to its video on-demand service, which was a less compressed HD stream. The high price of 4K televisions will put many off but with Netflix offering the streams at least those with the money will now have some content thus breaking the chicken and egg situation of what to watch that exploits your recent purchase.
With a movie weighing in at around 12GB if running at the expected bit-rate the need for an unlimited broadband connection becomes very obvious. For those with superfast broadband connections the 4K streams may still offer an improved picture, even when viewed on a 1080p TV.
Another subtle change for Netflix is that the iOS app now supports HD streaming, so if you've just seen your mobile data use suddenly increase and you use Netflix on train/bus heading to or from work then this may be the reason why.