Microsoft is making the move not to increase the number of paying Hotmail users but because the feature is being abused by senders of spam, said Brooke Richardson, lead product manager for MSN at Microsoft.
Source: ITworld.com
As EvilSeph said, it was announced months ago. Existing accounts are/were able to access the service a short while longer, while new accounts did not have this possibility at all anymore.
Amongst additional sources are articles from
ZDNet.com and
BBC Tech News.
/ 
