PowerPivot on SharePoint 2010

[MD610]

I have a question about publishing PowerPivot workbooks to SharePoint 2010. My company has been using a PowerPivot workbook that was mostly built using cube functions in excel. There are a couple variable fields in the workbook where the user can change the values to test our different scenerios. If this workbook was published to SharePoint, would the user still be able to easily change the variable fields from the published workbook in the browser? If not through PowerPivot Services for SharePoint, could this be accomplished using Excel Services for SharePoint?

I have little direct experience with either so any information would be helpful. Thanks!