It would be nice to have sound isolating ear cushions to fill the cavity where the speakers sit and create a tighter seal with the ear. Something similar to the SPH10 ear cushion.
This would reduce external noise and increase the clarity and audibility of the speakers. The hope is that this will also eliminate the need to wear ear plugs while riding (which sometimes blocks too much ambient noise and can be uncomfortable).
Conference intercom would be a nice addition to the SMH5 model line as well.