I't's been like that since late 2008...
No - in late 2008 when the unibody 13" macbook and the 15" macbook pro were launched, both supported removable/swappable batteries. The first generation 17" unibody macbook pro (i.e. Early 2009) was the first unit to use Apple's new battery technology and it was the first of the unibodies to support an integrated non-user-removable battery. In Mid-2009, the 13" macbook pro was introduced (replacing the 13" unibody macbook) and it along with the 15" macbook pros were also updated to include the integrated battery.