Well Jeremy, my situation is somewhat similar to yours in that i grew up in little Sherrill (Mayberry North), population 3000, in Upstate N.Y., which is close to Vermont, and then moved out west during and after high school. First Utah and then finally Sacramento CA. Most of my trials and tribulations in Utah were of a cultural nature, as we were Irish Catholics from N.Y. and not used to the absolute stranglehold the predominate religion has in that state. Lets just say it was the only place I have lived where I felt the sting of discrimination, and also the only place I have lived where a Jew is considered to be a gentile. My dad got tired of that scenario and moved the family to Sacramento right after I graduated from high school, and I continue to live in "The Big Sack" at this time.
If you are planning to hike in the Desolation Valley/Lake Tahoe area I don't think you will have to change your gear much from your Northeast setup. Keep in mind though that the mountains here are much higher than Vermont, often 10-11 thousand feet, or even higher. You may even be interested in completing the OGUL list of the 63 highest peaks in the Lake Tahoe area. The Desolation Valley is beautiful, and rivals anything in the Rockies, but it is hardly desolated. You better get to the trailheads before 9AM if you want a parking spot. In the winter we have the Auburn State Recreation area, which is located 20 miles from Sacramento, for hikers that don't like snow.
In the summer and shoulder seasons I bring a fleece or Thermawrap, warm hat and gloves, sometimes a Dri-Ducks rain suit, but mostly a water resistant windbreaker that also serves as a rain jacket. There is bountiful spring run off on the Sierra mountain trails, so you may want to consider Gore-Tex during that time. Personally, I don't like the stuff. There is no snow in Sacramento in the winter, but the Sierra (no s please, its singular) get tons of snow and the main arteries to the mountains, I50 and I80 often have chain requirements, (no studded tires allowed) or are even closed. We have lots of Poison Oak and ticks below the snow line, about 4500 feet, but none above which includes the entire Desolation Valley/Lake Tahoe area. I think your winter gear from Vermont will work just fine in our mountains in the winter.
Finally, I want to warn you about a certain elitist snob attitude that you may get from a minuscule number people who live in the Bay area. Mostly from folks in San Francisco and Marin county, and to a lesser extent from folks in the East Bay because they have less to brag about. Usually they will mention the smog, heat, suburbs, and lack of cultural amenities etc. here. Yes we have smog here, but a lot of that is generated in the Bay Area and blows in through the Carquinez Straits, so they sort of lose the moral high ground on that one. Yes it gets hot here in the summer, but rarely 110 like some one mentioned, and the humidity is usually below 50%. Back East the humidity is often 80-90%. Westerners can't even fathom how oppressive that is. I was on Tinny's blog the other day and he was mentioning 100 degree heat and 90% humidity in Maine! No thanks!
And suburbs, are you kidding me? There are plenty of suburbs in the Bay area, almost all of Contra Costa and Alameda counties along 680 and 580 are suburbs and strip malls--and I might add, with worse traffic than Sacramento. The bottom line is, don't listen to them, just come out here , check it out, see if you like it, and make your own decision. I don't ague with them, I just smile and wave as they roar through Sacramento at 95 MPH on their way back from a skiing trip in the winter and then get stuck in stop and go on the Yolo Causeway.