This is an Automattic service ment to backup your WordPress blog in realtime. You'll never lose any data again. And you'll forget about backing up ever 😉
I've payed for the personal blog level wich is $15 / month. Hey, it's even less if you pay in euros 😛
The time you sign up you'll have access to the VaultPress Dashboard. With your blog list, activity log, stats and downloads (uploads, plugins, themes...).
It will also add a new menu in your WordPress dashboard with some of that info.
Server side problems
The main handicap in this project is the amount of resources it uses to backup your data in real time.
In the images below you'll see how my shared hosting account creates spikes in the day it started.
As you can see the big one shows the full initial backup and the small ones the tiny backups.