Q u o t e:
I just got to the part in Silverpine / Gilneas where I'm bringing Crowley back, and after turning in the quest everything disappears and I'm left with a corpse and no NPC's. Can't turn in Resistance is Futile either as I cant get to my quest giver.

Halp?

Yep, if you turn in A Man Named Godfrey before you turn in Resistance is Futile you'll be stuck. This is fixed in the next build/patch.

Sorry for the inconvenience.

Q u o t e:

Not yet fixed as of August 6, 2010.

Are you on either quest right now (as in, are they in your log)? If not, check back at Emberstone Village.

Q u o t e:

Here's what I did:

- went with the questgiver to Tempest Reach killing 19/20 mobs on my way
- found the corpse on the beach, turned in the quest
- went back to the road with the quest giver to kill the last mob
- killed the 20th mob, turned in the quest and the quest giver went poof
- fought my way back through the elites to Emberstone Village to see if he's there
- no quest giver at Emberstone Village
- fought my way back through the elites to Tempest Reach to see if he's there
- finally found him on the beach with the follow-up quest

The quest giver should not disappear, no matter which quest you turn in first.

The questgiver(s) do not disappear until both quests are turned in. The problem here is that you went back to finish the Resistance quest and thus missed when the questgivers that were following you despawned and the beach questgivers spawned. It's a simple logic issue that will be resolved.