This service will be provided by Apple Authorized Service Provider Go Tech Services, meaning that it won’t actually be Apple themselves repairing your device, but it’ll be authorized by them. On Apple’s Support website, it reads, “Look for an Apple Authorized Service Provider or Genius Bar. In select locations, onsite service may be available.”
At the moment it does not seem that this option will be available in all cities. It is possible that maybe this service will be provided by a different company in other cities, but for now it seems that Go Tech Services is the only one providing these services at the moment. Apple’s website also notes that there could be an additional fee for onsite services, in addition to the cost of the repair, but they do not mention how much that would be.
It’s actually not a bad idea to provide onsite repair services, especially if you’re a company that works with a lot of Apple products.