As per the title....
I think its a reasonable idea to combat high utilisation at peak time. it is certainly the cheaper way (the alternative to upgrade the network). However as we have noticed recently the V stuff backup is being throttled, and lots of gamers are facing lag and generally bad gaming as the games use p2p hosting systems.
Another point is that people with fast connections, described as 'unlimited' should be able to download what they want, when they want.
Another point is that this could create a 2 teir internet, the reason why BT scrapped its plans to cache catch up TV services. (i dont agree with this, its a load of rubbish)
in my opinion, p2p software, in particular torrents were created as a way to speed up download speeds, and download from multiple sources at once. On faster connections, which is what you pay for from virgin media, you want to utilise this speed.
please vote and leave your opinion!

---------- Post added at 16:28 ---------- Previous post was at 16:17 ----------
okay, so if they targeted torrents, then maybe, but have you tried playing call of duty between 5pm and midnight. its up and down like a yoyo
---------- Post added at 16:35 ---------- Previous post was at 16:28 ----------
How about if they kept the current system in place, but allowed a minimum of, say, 5megabits, so you can be throttled to mimimum priority, but you will never get less than 5meg???