The files are intended to be concatenated into a single file named: Warhead-US-DOJ-LEA-2013.aes256
(US-DOJ-LEA = United States - Department of Justice - Law Enforcement Agency)
aes256 is apparently the encryption scheme used to encrypt the files.
File names (and sizes): 1115 MB total
Scalia.Warhead1 (150 MB)
Kennedy.Warhead1 (108 MB)
Thomas.Warhead1 (150 MB)
Ginsburg.Warhead1 (150 MB)
Breyer.Warhead1 (150 MB)
Roberts.Warhead1 (23 MB)
Alito.Warhead1 (150 MB)
Sotomayor.Warhead1 (101 MB)
Kagan.Warhead1 (133 MB)
The contents are various and we won't ruin the speculation by revealing them. Suffice it to say, everyone has secrets, and some things are not meant to be public. At a regular interval commencing today, we will choose one media outlet and supply them with heavily redacted partial contents of the file.
Should we be forced to reveal the trigger-key to this warhead, we understand that there will be collateral damage.
It is our hope that this warhead need never be detonated.
Summary: the file contains "various secret contents", the file has one encryption key to reveal all data, they intend to release previews of the data, they may not release the encryption key (although chances of this seem unlikely).
The encrypted data is almost certainly larger than the unencrypted data, my guess is the unencrypted data is closer to 600MB to 900MB (In the ballpark of the size of a standard 700MB data CD).
Initially I thought the 9 files may contain data about each of the SC Justices, or perhaps information intended for each of them. However, I think their names on files were simply chosen for effect.