Well, now I think I do - thanks mainly to the references at the beginning of a recent Article 29 Data Protection Working Party Opinion on Cookie Consent Exemption which itself is well worth a read (here's Andrew Cormack's summary). For your delight and delectation, here's what I think the changes are - all in Article 5.3 of Directive 2002/58/EC as amended by Directive 2009/136/EC:
3. Member States shall ensure that theSo there you have it.
use of electronic communications networks to store information or to gain access to information storedstoring of information, or the gaining of access to information already stored in the terminal equipment of a subscriber or user is only allowed on condition that the subscriber or user concerned is providedhas given his or her consent, having been provided with clear and comprehensive information in accordance with Directive 95/46/EC, inter alia about the purposes of the processing , and is offered the right to refuse such processing by the data controller. This shall not prevent any technical storage or access for the sole purpose of carrying out or facilitatingthe transmission of a communication over an electronic communications network, or as strictly necessary in order to providefor the provider of an information society service explicitly requested by the subscriber or user to provide the service.