Actually the loaded chamber indicator might be easy to implement but the requirement as of 01/01/2007 is a magazine safety too. That is, a device the stops the gun from firing unless the magazine is in the gun and fully seated.
The result of these two new requirements (done by law, not regulations) is that only modern new designs like most of the plastic guns and S&W semi-autos will be available in California. This is all part of the gun-ban'ers plot to take away gun rights a little at a time since they in no way can do it blatantly.
The trick is to buy every handgun that does not have these safety features that is on the CA DOJ Safety approved list before each individuals gun's certification runs out (expiration is varible dependent on when each gun was last certified---go to http://ag.ca.gov/firearms/
for the latest list and look at the expiration date column for the gun of interest).
What freaks me out is what little press this massive change is getting. It won't happen all at once (only when certification runs out) but over the next few years the list will get shorter and shorter. This will keep it out of the news as it will just kind of phase in before the public recognises what is happening. Sure wish I knew how to get some publicity on this into the publics hands. Unfortunately I think the manufacturers have given up on California and written it off for future gun sales.