John Gruber, Daring Fireball:

Now that iCloud is up and running and seemingly holding up under demand, Apple needs to start offering more than 5 GB of storage at the free level. That’s not even enough to back up two iOS devices — and Apple certainly doesn’t want to discourage people from buying additional devices or from backing them up to iCloud.

Amen. Apple should offer an amount of free storage per registered device, ideally 5 GB as Lex Friedman suggests.

I do somehow manage to fit an iPhone and iPad backup into the 5 GB, but it's tight.