Although last week some iCloud users realized that Apple offers them 20 GB of free space until 2050, in reality it was a mistake because only former MobileMe customers benefit now of a promotion from Apple and receive 20 GB of free space until September 30, 2013. Initially, Apple offers this space until September 30, 2012, but it made the decision to expand free for one more year as a sign of thanks for the loyalty of those who paid for the imperfect MobileMe.
Apple offered between 10-50 GB of free space in addition to the 5 GB received by any user, so now most former MobileMe users have enough available space to store their important data. The promotion does not apply to normal users either, so don't check the iCloud settings menu because you won't find anything new there.
