It's not obvious how Sky will "launch" their HDTV. A Sky installer is required for 1st time installation, but once you've already got a dish - with HD presumably from existing transponders - would a further installer visit be needed, except for new subscribers without dishes?
Maybe so, since most people aren't technology minded, and might have trouble connecting a new receiver, even if it's just a few leads. I suppose Sky will still want to know the equipment's been certified as connected and working. On the other hand, it would cost them less to deliver receivers by courier.
Don't know if I entirely agree with Rolf. CRT televisions are now getting more difficult to find - in "watchable" screen sizes - so many people will be buying LCD/Plasma etc. Then, once you've got a DVI/HDDI input, and already have a dish, it's a small step to get a HD receiver for films/sports etc, especially if Sky offer an attractive "package upgrade" via their subsidies.
(regardless of what can actually be seen on 720p vertical screen resolution!).