Channel 4's replacement for 4oD will launch Monday and is called All 4. The service aims to add more features and from launch you'll be able to watch live streams of Channel 4's services on your mobile device.

But that device will need to be made by Apple, at least to start with, because Channel 4 is only launching with support for the iPod, iPhone and iPad. You will be able to watch on a desktop computer though, and for now services like those provided on YouView and Virgin boxes won't change.

One massive disappointment with the new service is that it won't have any HD streaming at launch, and according to a Channel 4 spokesperson adding it isn't a priority, saying "we believe it is best to concentrate on other services that our viewers tell us are more important to them on these devices – such as HDMI / Airplay. We’ll continue to assess viewer appetite for new features through user research - and we’ll remain open to exploring the possibility to delivering HD programming on selected additional platforms".

Not a no to HD then, but very much not a yes either.

The service will feature a newly redesigned look and interface. Viewers will be able to chose from catch-up services, live streams and trailers and online-exclusive material to view. Registration will, however, be required to watch full-length programming.

As good as All 4 sounds, it is somewhat unclear why Channel 4 has opted to make it such a minor update to 4oD - which is already great. If you're going to the expense of re-launching, then why not go all out and modernise with HD and support for as many mobile platforms as possible?