I'm a big fan of cloud storage capability. Since I work on one computer and keep another at home, I have to use a flash drive or email myself to keep my files with me at all times. With this new functionality, you'll be able to upload one or multiple files to Google Docs. Each time you upload a file, you'll be notified how much space you're using and how much free space you have left. Don't forget: you're always able to purchase additional storage space.
For more on folder sharing, read more.
The second exciting and useful function: sharing folders with collaborators. Create folders in Google Docs and drag relevant documents and spreadsheets into each folder. Then share the folder as you would share a regular Google Doc. One note: you will be able to share files within the folders that haven't been converted to Google Doc format, but you won't be able to collaborate on these files.