The cablecom web site tells me that where I currently live (Geneva champel), their digital TV plans are not available.

Does anyone know if this is the case for the entire Geneva region? It seems I'll have to get either Swisscom TV or Nexoo!?

Look on Comparis and see what's available in your area:
http://en.comparis.ch/telecom/adsl.aspx

I know Geneva is being built out with a lot of fiber optic connections, so if you don't have many choices right now, you will very soon.

Group E is building heavily in the French-speaking part, maybe look at them:
http://www.groupe-e.ch/disponible-chez-vous-0