The Internal Revenue Service's latest data on the migration of taxpayers from one state to another has been released for the years 2010 and 2011. Back in 2012 the IRS announced it was discontinuing this series, but after protests from, among others, the Washington Examiner editorial page, reversed itself and promised to continue the data series.
The 2010-11 data shows that, as in the past, there is a large migration away from high-tax states to low-tax states. The biggest gainers were the two megastates with no state income tax: the net gain in taxpayer income from migration was $4.9 billion in Florida and $2.4 billion in Texas. The biggest losers were high-income-tax states: New York (-$3.3 billion), Illinois (-$2.0 billion), New Jersey (-$1.7 billion) and California (-$1.0 billion). That amounts to a net transfer of more than $7 billion to those first two states from the latter four.
Here is a spreadsheet with calculations from the IRS data by Jim Pettit, author of an article in Human Events on the subject, showing the net in-migration and out-migration of income to and from states in millions of dollars and in percentage of preexisting income tax base: