Microsoft has listened to some of the large corporations who wants to move to Office 365 by increasing the maximum size of the message that can be moved to Office 365.
Previously, the largest email that could go into Exchange Online was 25MB. This has now been increased six folds to 150MB. I am sure this will satisfy most (if not all) of the customers out there looking to move their large emails into the cloud.
There is no change to the other limits like mailbox size, maximum message size limits for sending & receiving. The increase is purely for messages that comes from customer deployments to O365. The Office 365 service description has been updated with the new limit as well.