We now have the BBCi player, more video sites, more video programs (Miro, Vuze), more streaming music sites and yet the bandwidth limits have not changed since the unlimited use was stopped.
The time must either be right or very close to Zen taking a look at what products they are selling?
I also think it would be very useful for Zen to produce figures such as how much bandwidth watching one hour of BBC New online consumes, how much one hour of last.fm and other popular online activities. I know that quality=more bandwidth but many services are fixed in output.