Your Surly New hubs use adjustable cartridge bearings (like many threadless headsets) so that the 'play' that develops as bearings wear may be adjusted out. This will allow longer life from the bearings assuming they are adjusted properly.
They adjust like loose-ball hubs, in that they work on a cone and locknut system. If you know what that means, you may already know how to adjust them. Regardless, if you are not sure what you're doing we highly recommend taking them to a competent professional bicycle mechanic. If you think you might know how to do it but just have some questions, feel free to contact us. The long and short of it is this: make sure your Surly hub bearings are properly adjusted, and when they need adjusting have them adjusted by someone who knows what they're doing.
Our New model hubs all use 7901 series adjustable sealed bearings. The black seal should always face outboard. Or if you want to take the guess work out of the equation try 6901 series non-adjustable bearings.