According to the Google Enterprise blog,
Starting next week, new schools that migrate to Google Apps for Education will see 25GB mailboxes. Existing customers will see their mailboxes grow over the course of the next few weeks.
Although this is a nice move from Google, especially for schools migrating from large Exchange or Lotus Notes implementations, most people don’t tend to hit their email quotas. Where they do often hit their limits is within Google Docs storage, which remains at a mere 1GB (more can be purchased, but the beauty of Google Apps for Education is the robust set of services offered for free). I have to hand this one to Microsoft – If organizations (or even individual users) truly embrace the cloud, then they shouldn’t need to have Box.net accounts for additional free cloud-based storage. One cloud to rule them all, right? –Google steps up its game with larger Edu Apps inboxes | ZDNet.