Just found this:
Create basic spreadsheets from scratch.
You can start from scratch and do all the basics, including changing the number format, sorting by columns, and adding formulas.
Upload your spreadsheet files.
Upload spreadsheets or worksheets from CSV or XLS format - all your formulas and formatting will come across intact.
Familiar desktop feel makes editing a breeze.
Just click the toolbar buttons to bold, underline, change the font, change the cell background color and more.
Looks like an interesting app and another example of Google gnawing away at Microsoft Office. Interesting though that it allows multiple people to work on a spreadsheet at the same time.
The beta is closed so you have to sign up to access it and go on a FCFS basis.