Linux 3.7 has not been released . While penguins finish the redaction of this page, you can take a look at these articles:
LWN [https://lwn.net/Articles/518275/ Merge window part 1], [https://lwn.net/Articles/518711/ merge window part 2], [https://lwn.net/Articles/519883/ merge window part 3]
H-Online Kernel Log - Coming in 3.7 [http://www.h-online.com/open/features/Kernel-Log-Coming-in-3-7-Part-1-Filesystems-storage-1750000.html Part 1: Filesystems & storage], [http://www.h-online.com/open/features/Kernel-Log-Coming-in-3-7-Part-2-Networking-1752099.html Part 2: Networking]
1. Prominent features in Linux 3.7
2. Driver and architecture-specific changes
All the driver and architecture-specific changes can be found in the [http://kernelnewbies.org/Linux_3.7_DriverArch Linux_3.7_DriverArch page]
3. Various core changes
VFS: don't do protected {sym,hard}links by default (breaks things) [http://git.kernel.org/linus/;a=commit;h=561ec64ae67ef25cac8d72bb9c4bfc955edfd415 (commit)]
4. Memory Management
5. Networking
Near Field Communication (NFC): Add an Link Layer Control(LLC) Core layer to HCI [http://git.kernel.org/linus/;a=commit;h=67cccfe17d1b3da1ed6c79e643c9be95ebde9642 (commit)], add an shdlc llc module to llc core [http://git.kernel.org/linus/;a=commit;h=4a61cd6687fc6348d08724676d34e38160d6cf9b (commit)], LLCP raw socket support [http://git.kernel.org/linus/;a=commit;h=4463523bef98ff827a89cf8219db7dfac4350241 (commit)]
6. Block
UBI (Unsorted Block Images), targetted for flash devices: Fastmap support. Fastmap is a mechanism which allows attaching an UBI device in nearly constant time. Instead of scanning the whole MTD device it only has to locate a checkpoint (called fastmap) on the device. The on-flash fastmap contains all information needed to attach the device [http://git.kernel.org/linus/;a=commit;h=dbb7d2a88d2a7bd3624e090bee42cdee048d9290 (commit 1], [http://git.kernel.org/linus/;a=commit;h=1c865749999efdae63ddfb73b911ee04e1d4e1c8 2], [http://git.kernel.org/linus/;a=commit;h=dac6e2087a4143cfc3fc1017bf24b9d4be3055b7 3], [http://git.kernel.org/linus/;a=commit;h=5638b33abffd967dda4f984a247925b7af38b23d 4], [http://git.kernel.org/linus/;a=commit;h=8199b901a31b6e89b63842643f644fc05b403b20 5], [http://git.kernel.org/linus/;a=commit;h=00abf3041590da6ad7533bf592e8dd452820109f 6], [http://git.kernel.org/linus/;a=commit;h=a7306653705e456c8affeb4efe9542b9f6b757ad 7], [http://git.kernel.org/linus/;a=commit;h=8974b15c6e84e686201d382c7d459aa9c8c96572 8], [http://git.kernel.org/linus/;a=commit;h=76ac66e469f084d41742ba08923de76fbdc7dce3 9)]
DM RAID: Add rebuild capability for RAID10 [http://git.kernel.org/linus/;a=commit;h=4ec1e369af83f7ecdfbd48a905e44fc9910115ba (commit)]
MD: raid5 trim support [http://git.kernel.org/linus/;a=commit;h=620125f2bf8ff0c4969b79653b54d7bcc9d40637 (commit)]
7. Crypto
RSA: Implement signature verification algorithm [PKCS#1 / RFC3447] [http://git.kernel.org/linus/;a=commit;h=612e0fe99965a4028359cd1da5af56b7f6caf7f6 (commit)]
X.509: Add a crypto key parser for binary (DER) X.509 certificates [http://git.kernel.org/linus/;a=commit;h=c26fd69fa00916a31a47f5f096fd7be924106df8 (commit)], add an ASN.1 decoder [http://git.kernel.org/linus/;a=commit;h=42d5ec27f873c654a68f7f865dcd7737513e9508 (commit)], add simple ASN.1 grammar compiler [http://git.kernel.org/linus/;a=commit;h=4520c6a49af833c83de6c74525ce8e07bbe6d783 (commit)]
8. Security
Smack: implement revoking all rules for a subject label [http://git.kernel.org/linus/;a=commit;h=449543b0436a9146b855aad39eab76ae4853e88d (commit)]
9. Filesystems
- xfs
Make inode32 a remountable option [http://git.kernel.org/linus/;a=commit;h=2ea0392983a82f7dc3055568ae0f2558724d119b (commit)], make inode64 a remountable option [http://git.kernel.org/linus/;a=commit;h=c3a58fecdd1934a8538ada9073107625f5151687 (commit)]
Make inode64 as the default allocation mode [http://git.kernel.org/linus/;a=commit;h=08bf540412ed82a15cb9068249ad49b410a7b082 (commit)]
NFS: Introduce "migration" mount option [http://git.kernel.org/linus/;a=commit;h=896526174ce2b6a773e187ebe5a047b68230e2c4 (commit)]
UDF: Add support for O_DIRECT [http://git.kernel.org/linus/;a=commit;h=5eec54fcde7e065eb3d8a6e70e61d90673ca706b (commit)]