I've been trying the FireCommandEvent() to post grid updates from outside the grid (via "Save" button). Some of my grids are using InPlace mode, and others using EditForm. For the those using InLine, I've been able to iterate through the EditItems collection and fire the event successfully. Unfortunately, the EditItems collection does not contain EditFormItem is not accessible for items in the EditItems collection. In the meantime, I've been able to cast it as GridDataItem and access the EditFormItem for firing the event.
for(int i=0; i < this.RadGrid1.EditItems.Count; i++)
(this.RadGrid1.EditItems[i] as GridDataItem).EditFormItem.FireCommandEvent(RadGrid.UpdateCommandName, String.Empty);
It's not the most elegant solution, but it works. Is that something that'll be available eventually?