That's what 20 MB blocks require. That means, you receive the blockchain, that's 84 gigabytes per month. You send the blockchain to one peer, that's another 84 gigabytes per month.
Gavin's proposal doesn't have 20MB blocks begin until Mar 1 2016. Even after that date, it's incredibly unlikely that we'll have 20MB blocks until several years afterward. Bitcoin will need more bandwidth in the future, not less - luckily technology doesn't stand still and the cost of moving lots of data will come down and be available to many more citizens around the world.
Just like the needs for streaming HD movies will go from 1080 to 4K over the next few years, so too will the hardware requirements for bitcoin. Don't worry - there will be plenty of people to run nodes.