This info is on the DOS payroll update section at qwpage.com, but applies to NV2 as well:

(Except from T4127, Payroll Deductions for Computer Programs, 85 Edition)

The Minister proposed a new non-refundable tax credit amount of $2,000 in respect of children under 18 years of age at the end of 2007. If a child born in 1990 or later resides with both parents throughout the year, either parent (but not both) may claim a $2,000 personal amount. Any unused portion can be transferred to that parent’s spouse or common-law partner. If the child does not reside with both parents throughout the year, the parent who is entitled to claim the amount for an eligible dependant can claim the amount for child tax credit.

The Minister proposed increasing the spouse or common-law partner amount and the amount for an eligible dependant from a maximum of $7,581 to a maximum of $8,929. The amount will be reduced by the partner or eligible dependant’s net income for 2007.

A revised Personal Tax Credits Return TD1 will be available for July 2007.

Bottom line: Employees should fill out a new (Jul 07) Federal TD1 and you use the revised claim amount they supply in their payroll setup (Deduction Information, Federal window.). The $2,000 is not entered separately anywhere in the payroll.