Obamacare is driving a transformation in the way pharmacies do business, so get ready. The healthcare reform law will expand access to medical services for millions of people. That's going to place added pressure on primary healthcare providers and challenge the system to meet the new demand. So it may not be surprising that the nation's three major drugstore chains are gearing up to play a bigger role. They're placing retail health clinics in their stores, pushing their pharmacists to be more proactive with their prescription customers, and even entering partnerships with big medical groups.