It sounds like utter bunkum to me!
I've Googled loads of possible ways of identifying any forthcoming legislation and nothing shows up. Further, there's nothing about it on the Caravan Club website or on the main pages of Practical Caravan magazine's website.
Most importantly, however, there are no relevant posts on the Practical Caravan forum. The most recent post about parking on a driveway was only a month ago, and it attracted a large number of responses (including some from people with a quite detailed knowledge of the law). None of the responses made any reference to any proposed changes to current legislation:
http://www.practicalcaravan.com/newforums/fm_m essages.asp?FO=5&FM=366284
If you're still unsure, why not join the forum and post your question there? (I'm confident that you'll get the same answer). The home page of the forum doesn't appear to have a 'register' link but you can find it by clicking on 'login':
http://www.practicalcaravan.com/newforums/fm_f orums.asp
Chris