I'm actually a dual citizen, so I can go up anytime, I believe.You don't even need to be a dual citizen -- if you're a citizen of the US or Canada, have a job offer, and have reasonable qualifications (a Bachelor's degree in most fields is enough) you can drive up to the border, mention NAFTA, and get a visa on the spot.
are there good reasons for me to go from the bay area to Vancouver
I haven't lived in the bay area, and I don't know your circumstances, so it's hard for me to give a good answer here. I know when Google offered me a job in Mt.View, one of the factors which led me to not accept was that between Vancouver and what I had seen of the bay area, I much preferred Vancouver -- but I grew up in Vancouver, and my tastes have probably been molded by that. If you grew up in a dry, polluted, urban sprawl, you might prefer the bay area.
I imagine I would just be paying more in taxes...
Don't be so certain. Canada has publicly-funded health care, which tends to raise taxes, but it also has much lower per-capita military spending than the US. I can't make much sense out of US income tax forms, but Google found me http://dbaron.org/views/taxes-2007.html; comparing it to an analysis I did last year http://www.daemonology.net/blog/2007-05.html it looks like a single California taxpayer typically pays a marginal tax rate of about 40% of income while a single BC taxpayer typically pays a marginal rate of about 26% of income -- of course, in BC we have provincial and federal sales taxes which add a combined 12% to most things you'll be buying (does California have any sales tax? I don't know), and gasoline taxes which are higher than you have in the US. In short: I suspect that the difference between taxes you pay in the bay area and taxes you'd pay in Vancouver could be either positive or negative depending on your individual situation.
Then of course there's the issue of real estate costs: Vancouver is the most expensive place in Canada, but I understand that it's still far cheaper than the bay area...