I think the 2 minute delay is something that needs sorting if live streaming will be the future.
That's how streaming over the internet works.
How short is short enough to be acceptable? The live channels on YouView are a second or two behind real time (roughly on a par with DSat) but aren't really being delivered over the public internet.
I think if other broadcasters wanted to achieve something similar, they'd have to make their streams available as multicast to each ISP - which is then potentially going to come up against net neutrality rules.
Incidentally, I know it's not exactly easy for the average viewer to measure (other than by perhaps comparing against 5 Live commentary), but I think our UHD stream was only about 40 seconds behind; were 2 minute lags really that common?