Futurama is of course a great comic series. But this episode shows more than any other how it can strike a bittersweet, serious note as well with its spin on the familiar flashback of Fry's last day in the 20th century. This time, instead of seeing that Fry's coming to the future was not entirely as it appeared in the first episode, ("The Why of Fry" season 4) we get to see another aspect of his life that was left behind--his faithful dog Seymour. As the episode unfolds we learn what happened to Seymour after Fry was frozen...and what Fry decides to do when his fossilized remains are recovered in the future.
I think the song that's played in the last scene is perfectly chosen--and I came to IMDb to find out who sings it. I couldn't find that information here, but in case anybody else is wondering I found it on Wikipedia--"'I Will Wait For You' from The Umbrellas of Cherbourg as sung by Connie Francis, which writer Eric Kaplan's parents played and sang on the piano while he was a child."