My thoughts on timesheets - the majority of companies I work with using Project Online mostly care about "task updating" capabilities and not a "fully functional" timesheet. Often timesheets are tied to payroll or other functions that are not in the control of the Project Management Office. As long as the solution Microsoft provides includes a variety of options for gathering task updates (% complete, hours, etc.), I think most companies could use what is provided and traditional timesheets for pay would be addressed another way.