Sky will launch its high-definition TV service on 22 May, with Star Wars movie Revenge of the Sith and US drama 24 among the initial line-up.
The BBC is showing live World Cup coverage in HDTV from 9 June
The broadcaster will install its first HDTV boxes that day after taking 40,000 advance orders from customers since bookings opened on 13 April.
HDTV promises clearer pictures and sound, but viewers need compatible TVs and set-top boxes to receive it.
Cable firm Telewest is also offering HDTV services to its customers.
It is currently offering programmes on demand to customers who use its TVDrive service.
The BBC will offer live coverage of World Cup football on HDTV via Sky and Telewest as part of a year-long trial.
It has also teamed up with ITV, Channel 4 and Five to test HDTV broadcasts that can be picked up through normal aerials.
But this trial is restricted to a selected number of Freeview users in the London area.
Widespread HDTV broadcasts via Freeview may not be possible until after the UK has fully switched to digital TV in 2012.
Other highlights in Sky's first week of HDTV include Star Trek Enterprise, live coverage of England's second cricket Test with Sri Lanka and rugby union's Guinness Premiership final.