Here is an excerpt:
The issue is a politically sensitive one for California. In November, state voters passed Proposition 30, which raises tax rates 1 to 3 percent for those making more than $250,000 a year. The initiative is integral to California's new budget, which shows a surplus. But along with Washington's "fiscal cliff" solution – which also will raise taxes on the rich – there are questions about how California's millionaires will respond.
“If there is anything that can be termed a mass exodus, then I think that will be symbolically very important,” says Jessica Levinson...
Experts acknowledge that any migration effect is hard to gauge.