No need to worry just yet
@Andrew Jones 2: at the moment the bill doesn't affect you and your business because not only has no code of practice governing the initial obligations been approved one is yet to be drafted. As this article explains, there's still a lot of detail to fill in. That detail will, crucially, decide whether you will have anything to do at all and, if you are required to do anything, precisely what.
This is why lawyers are generally not rushing forward with guides to the DEA - anything we write now would be full of so many ifs and buts its not likely to be particularly helpful.
That is already the situation for an open wifi operator, as I observed a while ago, in theory you could be made to do a lot of work recording details of the use of your system, but in practice you aren't, see:
http://www.francisdavey.co.uk/2009/04/data-retention-and-open-wifi.html
I hope to post some more useful analysis of the DEA as the codes of practice become clearer.