HARRY: Becomes Head Auror in the re-formed Ministry of Magic
GINNY: Becomes a quidditch player, and later retired to become Quiddich correstpondant for the Daily Prophet.
HERMIONE: Hermione began her post-Hogwarts career at the Department for the Regulation and Control of Magical Creatures where she was instrumental in greatly improving life for house-elves and their ilk. She then moved (despite her jibe to Scrimgeour) to the Dept. of Magical Law Enforcement where she was a progressive voice who ensured the eradication of oppressive, pro-pureblood laws.
RON: Ron takes over Fred's position in Weasley's Wizarding Wheezes.
LUNA: She ended up marrying a fellow naturalist and grandson of the great Newt Scamander (Rolf)!
TEDDY LUPIN: Lives with his Grandmother, Andromeda. However, unlike Neville, who was also raised by his grandmother, Teddy had his godfather, Harry, and all his father’s friends in the Order, to visit and stay with. He is not a werewolf, Metamorphmagus like his mother.
PERCY: Became a high-ranking ministary official.
KINGSLEY: Became Minister of Magic after the ministary was re-formed.
GEORGE: Never gets over the loss of Fred, but names his first born (a son) Fred in memory. Is now working happily with Ron :)

Dumbledore and the mirror of desire:
What DD truly saw was his family alive, whole and happy — Ariana, Percival and Kendra all returned to him, and Aberforth reconciled to him.

Did Lily ever have feelings for Snape?:
Yes. She might even have grown to love him romantically (she certainly loved him as a friend) if he had not loved Dark Magic so much, and been drawn to such loathesome people and acts.

Do the rest of the wizarding world know about Snape's heroism?:
Harry would ensure that Snape’s heroism was known.  Of course, that would not stop Rita Skeeter writing ‘Snape: Scoundrel or Saint?’

Did Harry end up with the moterbike?:
Of course. Mr. Weasley fixed it up and gave it to him.

My most important question:

WHO KILLED REMUS LUPIN?!?!?!!
Remus was killed by Dolohov and Tonks by Bellatrix.

Hopefully that answered a few questions. It surely put my mind at ease. Now where's my gun, I need to kill Dolohov....