Folks may not pay for content online, but I'm betting they'll pay to keep their content online ... and so is Google.
From the Google blog
When you reach the limit of free storage (i.e., 1GB for Picasa Web Albums, 2.8GB for Gmail), consider this your overflow solution. Plans start at $20/year for 6GB (yes, $5 cheaper than before), with larger plans ranging up to 250GB.
Sounds like a pretty fair deal.