I have heard indirectly from the Microsoft EPG head honcho who said the plan was for the new listings to be released on the 27th so that they can be downloaded in time for the 28th. Sadly this is not true as at 08:10 GMT on 28th February all the old listings & channel numbers are still there. I forced an EPG download but still the EPG is incorrect.
Here is a link to all the new programme numbers http://www.digitalspy.co.uk/article/ds28384.html All TV channels remain as 3 digit numbers but all the radio channels are 4 digits with a leading zero. Unfortunately this now means that they will not be accessible from MCE.
Sadly this is all par for the course as regards the MCE EPG of course.
It worked for me too. It's bizarre that you don't get either ITV4 or Sky Three whereas I get ITV4 but no Sky Three. I have just had an email from someone enclosing a screenshot & he definitely does get programme listings for Sky Three. So it's not a generic Sky EPG problem.
What TV region are you? If you look in the Event Viewer -> Applications & look for the entry of the Media Center Guide download it will have all the details. I use a Chelmsford post code & the details n the log are Headend ID 210059 Headend name Sky Digital BBC1 East (W)/ITV London/Anglia
The guy with the fully populated EPG has a Headend ID: 210001 & Headend name: Sky Digital BBC Scot/ITV Grampian