I originally let the wallet just run without doing anything, hoping the blockchain issue would work itself out.  It did, as previously reported by others.  Then I had to restart the pc, and the wallet wouldn't open.  Same error as others have posted.

This worked for me, so far, with a couple wallet close/wait a minute/restart wallets:
I backed up the whole roaming/Diamond directory, then deleted everything except Diamond.conf and wallet.dat
I added only the one indicated addnode to diamond.conf(addnode=193.68.21.19), so there was only one.
I added all the files and the database folder from Original.rar and let it resync using
    diamond-qt.exe -loadblock=blk0001.dat.  
I "lost" about 2/3 of my coins from my balance, but the transactions were still visible.
I closed the wallet, waited 1 minute, then opened it again using diamond-qt.exe -repairwallet

This worked.  My balance is correct, including some Diamonds minted yesterday 6/26.
I closed the wallet, waited 1 minute, then restarted it with just diamond-qt.exe.  It opened, and the balance was still correct.
So I did it again to be sure.  Closed the wallet, waited, restarted the wallet.  It's still good for me.

I assume since I only have one addnode I am on the right chain.  I have the same checkpoint info utahjohn and paladin281978 have posted:
{
"synccheckpoint" : "000000005babbddb5baad7bb9632738ab901b2f9eb3acfd2f390b2f4a97f1eee",
"height" : 463183,
"timestamp" : "2014-06-26 16:46:41 UTC"
}

getpeerinfo gives me 6 peers all running the right "subver" : "/Diamond:2.0.2.1/",

Can popshot, cryptonit, or Danbi confirm that's correct?

The only issue is now I have a whole mess of orphaned mint transactions from yesterday listed as my most recent transactions, even though they are not.  Someone else asked, with no reply, is there any way to get rid of them, or at least make them sort properly in date order so they disappear off the screen over time?