The popular GDrive has been around for over a year now. If you use this Windows Explorer add-on then you can easily store files using the 2700MB in your GMail account. The problem is that Google does not authorize this service and could cause your account to get suspended.
There does appear to be a solution in the near future because Google has released information that hints at a file storage solution they will offer. They may only offer a limited size for free and offer an opportunity to upgrade for a small fee, but this will be another nice addition to the services Google has to offer.
One of the main reasons that the service would probably not be completely free is because it is more difficult for them to use contextual advertising in an effective way. Contextual advertising works by looking for text on a page and displaying advertisments related to that text. For example, in GMail, the advertisements displayed on the right side of the screen are gathered by reading the content in the email you are viewing.
So now we are waiting on the Google Calendar and this file storage.
News Source: Googling Google