A WiFi dimmer would be a great addition to the range.
Yes, this would be amazing. Both in the S20 style and Sonos Touch style. Would replace majority of use-cases.
I agree a version with dimmer support would be fantastic. If you do this please make sure it will support incandescent, CFL and LED lighting.
This would beat most other modules (Zigbee, ZWave, KaKu, etc).