I'm seeing poor speeds to certain locations on the Internet which makes me think the issue could be egress from the Sky network as a whole.
Using speedtest.net I can find certain sites that will provide full, flat-lined performance from my broadband connection (which is 4.6MBits/s from a ~5500 sync) - one example being the Namesco server. This shows that my local connection and traffic from my exchange (Bangor, north Wales) out to at least some datacentres in London is okay. No local exchange congestion.
However anything useful is currently barely scratching 1Mbit/s: iPlayer, YouTube, iTunes, , or most other speedtest.net sites. These continue to work flat-out on another broadband line on the BT network, showing that the problem is likely at point the data meets the Sky network.
I'd like to know if there's a reasonable chance this will be fixed soon - which I assume is more likely if it impacts many people. My speeds were good between joining in December and a couple of weeks ago, it seems to have gone downhill recently.