Beginning in 2012, filers receiving a refund will be able to get it in as fast as 5 business days. In prior years the fastest you could get a refund was 6 business days.
Direct Deposit refunds will also be deposited on Wednesdays instead of Fridays as it has been done in the past. It is unclear why the IRS has chosen Wednesday instead of Friday.
In order to get your refund in 5 business days you would need to e-file your return on a Wednesday morning by 11:00 a.m. EST. If you miss that cutoff, it will be 10 business days before you receive your refund since all IRS Direct Deposits are done on Wednesday's in 2012.
The most obvious reason the IRS is reducing the refund turn-around time is to discourage filers from taking out loans against their refunds. If you're receiving your refund in 5-10 business days, you shouldn't be borrowing your own money and paying hefty fees.