The poem ends unexpectedly, in my opinion. Homer finishes off the story with the suitors' appearance in the underworld, where Agamemnon makes a final appearance, rounding out the parallels between the Odysseus story and the story of the fall of the House of Atreus.
Then, after his reunion with Penelope, Odysseus makes one final journey - but not to fulfill the command of Tireseus, and appease Poseidon. Instead, he goes to pay a visit to his father. The relatives of the dead suitors seek their revenge, and it appears that there will be another extended blood-letting, but Athena intervenes and puts an end to the fighting.
The important question to ask is not how does the poem end, but why does it end as it does. Homer doesn't provide any direct answer; that task is left to you, the scholar.