DigitalSpy reports that Channel 4 have started broadcasting unscrambled versions of three of their channels via the Astra 2D satellite. It means that those who know how to can access those channels via a satellite TV unit without actually being subscribed to Sky - previously Channel 4's satellite broadcasts were only available via the Sky system, which unscrambled the encrypted broadcasts.
The BBC have made their channels available via unscrambled satellite broadcasts since 2003 - though when they first did so it was rather controversial, if I remember rightly, [a] because it meant the Beeb stopped paying Sky a fee for managing the scrambling/unscrambling of their channels, which pissed the satellite broadcaster off rather a lot, and [b] because some (Sky mainly) argued that unscrambled satellite broadcasts could be accessed outside the UK (in Ireland, mainly) where the Beeb wasn't licensed to deliver imported shows.
Channel 4's move to making its channels available via unscrambled satellite broadcasts is probably a sign they plan to join the proposed Freesat service, the subscription-free satellite TV service being pursued by BBC and ITV which would make a Freeview style digital TV service available to those parts of the country where the Freeview signal is not available - and allow people in those areas to access mutli-channel digital TV without the need to buy Sky.
Freesat is expected to launch next month.