I'm hoping that the next version of iTunes allows purchase to the cloud as an option. I recently bought the West Wing complete box set in HD. That's 150 episodes at 1.5Gb each which all wanted to down load straight away.
I had to cancel all the downloads then get Apple support to remove them from my download queue so that I can now download them as and when I want.
Having the option or even having itunes be a bit more intelligent when you purchase content wouldn't be a hard feature to ass to the next version of iTunes. iTunes needs to detect that you have purchased multiple items that exceed a user defined level say 2Gb a movie. So it detects that you have added several Gigabytes to the download queue and displays a popup that lets you know you are about to download X amount of data so for me it was 225Gbytes of information. If it give me the option to download all or store them in my cloud account to download later then that would be brilliant.
With iTunes I now only store the music I listen too on my device the rest of the TV shows & Movies for example are stored on the cloud and I just download them when I want to watch one.