I think tomorrow's game between Atalanta and Inter will decide whether it's a three-horse race or a two-horse race. If Atalanta loses to Inter, they'll be behind by six points, and I don't see them catching up again when they still have difficult matches to play.
I expect Napoli to win against Venezia so they don't have to worry about falling further below.
I see Inter winning that game or at least getting a draw. I don't think they will lose. My money is also on Inter winning the Scudetto this season. They managed to catch up with Napoli and overtake them, now let's see if they can hold on till the end of the season.
Judging by stats, Inter has the upper hand. They've won all last six matches against Atalanta and are most likely going to win tomorrow's game. The only worry I've for Inter Milan is fatigue. They played on Wednesday in the champions league and tomorrow they will be playing in the league, so there's less time for the players to recover. If they're not managed properly they may not be at their best and this might be a problem.