There aren't many devices that support 1440p, so it reasons that not much content would be available.
I think at this point most people have HDTVs, I would imagine the rate of new sales of 1080p TVs is lower or at least slowing down from earlier years.
I think you'll have better luck finding 4k content, as TV manufactures are going to be working hard on pushing the technology to consumers. To do so they will need content for people to watch on them. Sony was a big part of Blu-ray and has embraced 4k so it wouldn't be surprising if they were looking to help in 4k adoption
I haven't looked too much into 4k personally, because I'm too poor for it. Quick Search shows Sony is the biggest player in getting 4k out to consumers. The PS4 is rumored to be able to stream 4k. They also have a 4k distribution platform, that sadly only compatible with their tvs.
I guess if you really wanted to you could get this
They have a few 4k independent films available.
http://store.sony.com/p/Ghostbusters-(4K-Mastered)/en/p/BDC42615Edited by Apinchof - 7/7/13 at 7:07am