After announcing that there will be no need to be worried about storage quota (see http://blog.hametbenoit.info/2015/04/03/office-365-sharepoint-online-no-need-to-be-worry-of-site-storage-quotas/) and an almost unlimited storage space for OneDrive for Business, now Microsoft is announcing a huge increase for SharePoint Online sites.
It used to be 10 Gb + 500 Mb per licensed user, now it will be 1 To + 500 Mb per licensed user. This is currently in testing so may be rolled out soon.
It has been announced on the Office 365 Roadmap site http://roadmap.office.com/en-us#I-211-15675
Enjoy this new huge storage