As mentioned below, if your new position is a salary paying job, they'll use your current income to qualify you. So for example, if the new job you started in 2012 pays you $3,000 gross every 15 days, this means that your monthly qualifying income is $6,500. They will check your 2012 W-2 and recent pay stubs to make sure that this bi-weekly income is consistent. If you're not paid a salary, but commission instead, they'll average the past 2 years (including year to date). If for some reason your 2012 commissions were less than 2011, they'll use the 2012 commission income.
If you're worried that they'll use your previous income simply because they asked for those tax returns, don't be! Lenders must document 2 recent years worth of tax returns as part of the 2 year employment history that's required. Just speak to your Loan Officer and make sure you're being qualified based on the right amount. Good luck!
Senior Loan Officer
STERLING NATIONAL BANK
310 Crossways Park Drive
Woodbury, NY 11797