This is unequivocally good news. The first estimate (released a month ago) was 2.3%, and this comes after a final GDP growth for Q1 of 0.6% per annum. Street expectation for this number was 3.2%. In technical terms this is called "lighting a fire under equities" or "giving the market a solid kick in the jacksie". A good part of this growth is from inventory build which won't necessarily be sustainable, but it does indicate the US economy continues to show momentum.