Yes, the Raney nickel catalyst is different from simple, fine nickel powder. Raney nickel is prepared in two steps. First, the nickel is alloyed with aluminum and then in second step much of the aluminum is removed through a leaching process with sodium hydroxide. As the aluminum is removed two things happen. The resulting nickel-aluminum alloy becomes very textured and porous with extremely high surface area (sponge-like). Also hydrogen gas is liberated during the leaching process and some of it remains adsorbed on the alloy surface. This is the active catalyst that is ready for use.
$$\ce{2 Al + 2 NaOH + 6 H2O -> 2 Na[Al(OH)4] + 3 H2}$$
If you'd like to read more about the initial alloying process or the activation (leaching) step, see this Wikipedia article.
As an aside, Murray Raney discovered this catalyst (US1628190) in the late 1920's and he was the sole assignee. I'm guessing that W. R. Grace bought the patent rights from him since they hold the trademark on use of the term "Raney nickel"