That would be a big yes! California can be very difficult to add towers in some areas due to NIMBYs the better question is will Verizon be adding towers in places where there network is poor or weak is another question. Lake and Mendocino counties are petty bad for VZW. I am sure there spots where the other national providers are good in California and verizon is weak, but they're not that many.
Verizon is slowly getting to Lake and Mendocino counties in CA. Verizon is installing tons of sites in California. Southern California is a big target, just within this year.
Cali has a huge NIMBY problem. But the California market is one that no carrier in there right mind will give up on covering better. there is quite frankly too much money to be made.
To answer your question, Verizon is done adding any sites to Cali in the next 2 years!! Of Course Verizon is adding sites, now with that being said they do not need to add as many as Cingular needs to. Do you need better coverage in a specific area. The great thing with CDMA technology is that is much easy to from a frequency standpoint to add sites, then with GSM.