Could it really be? Rumors are flying that tomorrow (Tuesday) Google will open a beta for a new spreadsheet tool. This is quite a move, and one that will certainly turn up the heat on the Microsoft – Google rivalry.

Google Spreadsheet will have support for the Excel file format, a move that seems to be setting a direct course for competing with the ever popular Microsoft Office suite. When combined with the launch of Calendar and the acquisition of Writely, Google seems to have an eye of the market now controlled by Office.

Reports are that at 9AM, EDT Google Labs will be linking to the new application and allowing a limited number of sign-ups.