As of today for new Microsoft Exchange Online tenantes can now gain access to BES for free and exsisitng clients will here from MS soon.
From Micorosft: The Hosted BlackBerry for Exchange Online service is free; we’re cutting the price for new and renewing BPOS customers to $0 starting now. So, with the cost of your regular wireless bill, connecting your phone to BPOS or Office 365 will be free – whether you have a Windows Phone, BlackBerry, iPhone, Nokia E Series or any other phone with Exchange ActiveSync.
Please note: Mobile phone providers charge an additional premium for the BES data in addition to the Microsoft BPOSO365 hosted Blackberry Service.