I don’t know all the details, so it may not apply to everybody, but if you’re a SkyDrive user (or just have an account) you might be eligible for a free upgrade from 7 GB to 25 GB (I haven’t heard of anybody not being eligible, though).
- Log in to https://skydrive.live.com/
- Click “Manage Storage” on the bottom of the left navigation column.
- Click the magic button to upgrade your SkyDrive Free plan from 7 to 25 GB.
It is my understanding that this is a limited-time offer, so get on it. It takes about 20 seconds if you know your password. :)