I just went through this myself, last week. The local 'hacienda' (tax dept.) was not aware of the implications and practical application of the new rules - but they thought that maybe they had heard something about it at some time.
Anyway... so we popped over to the local foreign police dept. and checked with the people there - who gave us a preprinted form with the citation of the new law --- to give to the *
other* government department. Apparently this happens so often that they've prepared materials in advance.
I also got the person's name and phone nummber so that the tax dept could phone to clarify if they wanted to (they did).
What it came down to was that I, an EU passport holder, did
not require a residence permit or work permit.
The nice people at the police advised me to go to some office in Madrid and get the residence card anyway (not a
permit but a card) to have something convienient to show to people or institutions that are used to everyone having one. Thess are issued the same day as you apply and it's really not supposed to be that much of a hassle. When I'm back in Madrid I'll look up the specific info and post it here.
By the way, irrespective of all that, you will still need a NIE (a Number to Identify foreigners) for tax and social security purposes.
Grant