Disclaimer: HomeWork Solutions employees are experts in Employment Taxes, not personal income taxes. That said, we see these forms every day. If you have specific questions please see your personal tax accountant.
First off, here is a link to the IRS maintained version of the Form W-4.
This new version has substantial changes. Even some elements that haven’t changed have been rearranged. Starting from the top we do see some familiar things (provided you’ve read the “fine print” of the form before). The general instructions haven’t changed much but there are some clarifications about the adjusted child care tax credit as well as credits for other dependents. You’ll notice then that the bottom third of the first page is now the Employee Withholding Allowance Certificate with no allowance worksheet above it. The section is still the same with name, address, social security number, etc. The most important things here are filing status (box 3) and number of allowances (box 5), the same as it has always been. The major difference is that getting to your number of allowances is considerably more difficult.