This doesn't guarantee that Watson will find dramatic savings. It's dependent on your input, so it won't know to go looking for deductions if you haven't at least suggested something. This is more about eliminating omissions (say, due to changes in tax law) and streamlining the experience than it is exploiting obscure parts of the tax code.

Having said this, the team-up is still in its "first phase." H&R Block hopes to use Watson in other areas of its business, and the cognitive computing system should improve as it masters the nuances of the tax system. You're still a long way off from having AI do all the heavy lifting when tax time comes, but this might make a big difference if you'd like help filing and want assurances that you'll get as large a return as possible.