If you look at the slightly higher end of the "streamer" market (and I am sure Wiim are looking at those products) - you see the following:
1. Better Internal DAC's
2. XLR inputs / outputs (IMO more for 'professional' audiophiles)
3. HDMI ARC (for audio input) - IMO for seamless "spouse" friendly audio experience in a main living space (i.e. living room with TV) this would be ideal input to compete with the soundbars. The whole 'switching' to optical / switching between multiple remotes to control things totally puts other members of a family off using 'good' audio products - HDMI arc solves this IMO much better than optical
4. Display - start small - but possible multiple 'tiers' of hgher end Wiim products, I see a few reasonable prices products with 'full' android experiences now - this is also a space with a higher end Wiim product would need to go. (By reasonable I am talking $600/$700 but I imagine in a year or 2 we will see similar at $500 or less.
Here are 2 examples:
DMP-A6 Streamers,Eversolo DMP-A6
www.eversolo.com
and
FiiO R7 combines transmitter/decoder/amp/preamp/media playback functions into one unit. It features numerous connections and expansion capabilities and rich operating modes, providing an excellent desktop HiFi experience!
www.fiio.com
But even a small OLED display with album art for say $200/$300 - unlike most companies Wiim have the App with the album available and the ability to 'push' that art work to their devices from a users mobile app.