Owing less to your student loans will improve your "debt-to-income ratio," which is the portion of your monthly income that is used to pay off your existing debts.
Lenders look at this ratio when deciding how much to borrow from you. Some use something called the 28/36 rule, which specifies that no more than 28% of your gross monthly income goes toward housing costs and no more than 36% goes toward total debt. (Some mortgage lenders have even higher limits.)