By Jim Finkle BOSTON (Reuters) – MakerBot, a 3D printer maker which opened two new retail stores this week, is among the companies trying to bring the cutting-edge digital manufacturing technology to Main Street consumers, but skeptics say the rollout is premature. MakerBot, a unit of Stratasys Ltd, opened retail stores this week in Boston and in Greenwich, Connecticut, both of which are twice the size of MakerBots first store, 1,500 square feet in downtown Manhattan. For most people 3D printing is futuristic science fiction. Were here to make it real, said CEO Bre Pettis, who cut the ribbon at the store on Bostons fashionable Newbury Street using scissors made on one of MakerBots Replicator printers which start at $2,199.