We can't add a raised mark (as far as I'm aware) but we are arranging the layout so that the 1 and 4 keys don't do anything in normal playback mode - so if you hold it the wrong way round and try to change volume, nothing annoying will happen (apart from the lack of volume changing!).

The sample also has an activity LED in one corner, but I'm not sure if that will be present on the production models.

Rob