Saw this today from google:

http://googledrive.blogspot.co.nz/2013/05/bringing-it-all-together-15-gb-now.html

So instead of having 10 GB for Gmail and another 5 GB for Drive and Google+ Photos, you’ll now get 15 GB of unified storage for free to use as you like between Drive, Gmail, and Google+ Photos.

I am using google apps for domains and have not seen this size increase as yet? Anybody seen the increase?

Edit: I'm already a subscriber to the 100GB plan for $4.99 / Month but still limited to 10GB for gmail.