I just got back from the DMV where I registered my '74 914 without needing a smog certificate. There were rumors suggesting that the 30 year rule actually applied to the car's build date or first registration date (that would have meant my car wouldn't be exempt until October of this year). Apparently those rumors aren't true. I suppose others could have different experiences depending on how well informed your DMV agent is.
Anyone else out there with a '74 in California I would say the value of your car just went up a little. _IF_ the legislation holds this will be a good thing for owners of '75s and '76s in the next few years.
Jon