According to Ken Davidoff:
Astros indeed expected to get non-prospect minor-leaguer(s) and payroll relief from Yankees in return for Berkman.
In return, they won't have to give up any premium prospects in order to bring in the 34-year-old switch-hitter as their primary DH. David Adams and Ivan Nova have seen their names as come up as possibilities. Adams, a second baseman, was mentioned prominently in the Cliff Lee talks with the Mariners before that deal died.