UIActionSheet from Popover with iOS8 GM

To support iPad, include this code:

alertView.popoverPresentationController?.sourceView = self.view
alertView.popoverPresentationController?.sourceRect = self.view.bounds
// this is the center of the screen currently but it can be any point in the view

self.presentViewController(alertView, animated: true, completion: nil)

If you are presenting the action sheet after the user makes a selection on a cell within a UITableView. I found that this works decently well:

UIAlertController *alert = [UIAlertController alertControllerWithTitle:@"Directions" 
                                                               message:@"Select mode of transportation:"
                                                        preferredStyle:UIAlertControllerStyleActionSheet];
alert.popoverPresentationController.sourceView = cell;
alert.popoverPresentationController.sourceRect = cell.bounds;
UIAlertAction *defaultAction = [UIAlertAction actionWithTitle:@"Cancel" style:UIAlertActionStyleCancel handler:nil];
//...
[self presentViewController:alert animated:YES completion:nil];