This is truly significant. Writely was nothing spectacular. Calendar, okay, cool but not earthshattering, but taking on Excel brings back fond memories of the bloody spreadsheet wars of the late 80s. Back then BillG waited for Phillipe Kahn to slash prices and bundle the apps, once that was done Microsoft waded into the pricing game like a hippo into a tea party and before long Lotus 1-2-3 was a joke and Excel pulled off the biggest mass app switch in history.
Now, can Google get anyone to budge from their pivot tables?