Maybe it is and I'm just not aware of it. I left TV about four years ago, so not sure if the technology has made it to consumer file transfer tools, but as far as I know clients for services like Dropbox (mentioned below) don't use UDP.

If they do, and I just don't know about it, then the future is here!

Many games (if not most) use UDP for multiplayer functionality, as it's more bandwith efficient. UDP has no error recovery, packets are sent without any idea whether the receiver got them or not, and there is no handshaking the connection like with TCP, resulting in smaller latencies.