First, have a Potterdammerung bingo card. It'll be full by the end of this entry, trust me. You'll get a couple of these from me--guess which ones.
General Fandom Observations
Communities created because of DH (I'm not bothering to list ALL of them)
its_a_fake - Created as a result of the leaks. It may or may not be much better, wank-wise, later.
spoil_me_dh - It should be called wank_me_dh, what with all the wank going on. I'll have a subsection for the best of it when I get around to it.
remus_lives - A community dedicated to Remus Lupin after he got killed. I didn't even cry over him like I thought I would--he was, after all, in my top five favorite characters.
dh_epic_fail - For those who couldn't stand DH. It's starting to look good.
wtf_jkr - For those who wonder where or when JKR went wrong in her writing.
the_ass_ship and hp_ass - For AS/S shippers. Pretty much the best thing that came out the epilogue.
rip_snape - A place to mourn Snape
deathlyh_icons - A place for DH-related icons and requests
grindeldore - A place for Grindelwald/Dumbledore shippers
rowlings_inbox - Yet another letter-writing campaign to JKR, good or bad
ameinias on JKR's religious bent
g_solis on post-DH fanfiction
mercury_ca on what happens while reading DH
carentan on the founders' reactions to the leaked book
A mod post on DH spoilers. This thread is long and full of semantics, arguing over who's the better author and whether being spoiled really does ruin the reading experience. Where's semantics cat when I need him?
The Revelation of Harry Potter, courtesy of a thread in fandom_wank (I link the second half later)
On other HP comms
Book seven has been compared to fanfiction! And watch the reactions.
Oh no! JKR has abandoned the Potterverse!
Book seven is the worst book and I'm writing to JKR right now! Oh noes! This one found its way to stupid_free.
xenophilius wrote the first AS/S fic (that I can find)
The Daily Snitch - 21 July. Not exactly wanky, but tons of essays and reactions for reading.
The Daily Snitch - 22 July. More essays for reading.
Ginny's a slut!
On harrydraco, what if JKR wrote the epilogue to spite the slashers?
Hey, harrydraco, let's write an alternate canon! Yeah, like that's going to work.
What's up with all the James hate?
Mass suicide pact!
JKR is worse than Hitler!
The Slytherins deserve better!
Still on LJ
Courtest of cf_hardcore, the epilogue was all about popping out kids instead of having careers!
A H/HR shipper reads the epilogue after about 500 pages and hates it. The first comment thread wins, though.
DH Innuendo (and there were a lot of these!)
The Huge DH Wank Thread, including these threads of win:
Ship wank, and Voldemort ships Harmony!
Everything I know about Harry Potter I learned from Fandom Wank
from hp_cornfield: Hey ProjectHarmony, let's write to JKR and tell her what we think!
Yes, Virginia, there is a Potterdammerung. Snape wank ahoy. Looks like I've bingoed.
JKR hates gay people!
The Fandom Outside LJ and JF
Book Seven Parody
Over at Portkey, what would you give for the series to end H/Hr?
FF.net is already cranking out the fics. (The link is within LJ, but there are links to ff.net. You have been warned.)
Encyclopedia Dramatica article on Harry Potter. Some NSFW images.
Molly couldn't have killed Bellatrix--she was a mommy, and Bellatrix wasn't!
Farewell cruel fandom--from one of HarmonyForever's admins. The thread gets pretty good.
One person burned his copy of DH
The author's note of this fic slays me. JKR was mean to me!
Outside LJ and Fandom
Ginny Weasley and Hermione Granger. Yes, Wikipedia articles. Keep an eye on the talk pages--the debates surrounding the name change could get fierce.
From Time: Who dies in Harry Potter? God. (No spoilers, but here we go again.)
DH discussion on Slashdot. I'm not bothering to read all twelve pages, but there's some good stuff (i.e. wank) there.