Same here. just got the 4S and it restarts every 2 hours or so.
Here is the log file which I don't have a clue of what it means:
Incident Identifier: 884E2936-DA05-4723-B93C-24BE342C13B8
CrashReporter Key: bda506216a30d8c08b53cd2bbcb76a125f063fc5
Hardware Model: iPhone4,1
Date/Time: 2011-10-22 23:35:15.547 -0400
OS Version: iPhone OS 5.0 (9A334)
panic(cpu 0 caller 0x8064faf5): "sftl: lba mismatch; lba:0x1b30c, meta:0x1240ef62\n"@/SourceCache/IOFlashStorage/IOFlashStorage-558.4/WhimoryPPN/ Core/SFTL/s_read.c:30
Debugger message: panic
OS version: 9A334
Kernel version: Darwin Kernel Version 11.0.0: Thu Sep 15 23:34:43 PDT 2011; root:xnu-1878.4.43~2/RELEASE_ARM_S5L8940X
iBoot version: iBoot-1219.43.32
secure boot?: YES
Paniclog version: 1
Epoch Time: sec usec
Boot : 0x4ea378d2 0x00000000
Sleep : 0x4ea38acc 0x0008e816
Wake : 0x4ea38b59 0x00000008
Calendar: 0x4ea38b59 0x0006f47b
Task 0xc085ed20: 11177 pages, 109 threads: pid 0: kernel_task
thread 0xc09b1e50
kernel backtrace: cfd8be40
lr: 0x8007bccb fp: 0xcfd8be6c
lr: 0x8007c2cf fp: 0xcfd8be9c
lr: 0x80016391 fp: 0xcfd8beb4
lr: 0x8064faf5 fp: 0xcfd8bee4
lr: 0x8064fc5b fp: 0xcfd8bf34
lr: 0x80650135 fp: 0xcfd8bf50
lr: 0x806487a1 fp: 0xcfd8bf64
lr: 0x8063e291 fp: 0xcfd8bf80
lr: 0x8063e52d fp: 0xcfd8bfa8
lr: 0x8007a3bc fp: 0x00000000
Task 0xc085eac0: 214 pages, 3 threads: pid 1: launchd
Task 0xc085e600: 659 pages, 11 threads: pid 12: UserEventAgent
Task 0xc085e140: 223 pages, 4 threads: pid 13: notifyd
Task 0xc085e3a0: 686 pages, 11 threads: pid 14: configd
Task 0xc085dee0: 6186 pages, 20 threads: pid 15: SpringBoard
Task 0xc085dc80: 143 pages, 4 threads: pid 16: syslogd
Task 0xc085d560: 1854 pages, 20 threads: pid 19: CommCenter
Task 0xc085d0a0: 571 pages, 2 threads: pid 21: lockdownd
Task 0xc085cbe0: 271 pages, 2 threads: pid 23: powerd
Task 0xc085c260: 1400 pages, 13 threads: pid 27: locationd
Task 0xc085c000: 506 pages, 4 threads: pid 28: wifid
Task 0xc0ef0ac0: 696 pages, 8 threads: pid 30: ubd
Task 0xc0eee980: 1800 pages, 19 threads: pid 44: mediaserverd
Task 0xc0eee720: 395 pages, 4 threads: pid 45: mediaremoted
Task 0xc0eee4c0: 373 pages, 3 threads: pid 46: mDNSResponder
Task 0xc0eee000: 579 pages, 7 threads: pid 48: imagent
Task 0xc0f4cd20: 723 pages, 5 threads: pid 49: iapd
Task 0xc0f4c860: 181 pages, 4 threads: pid 51: fseventsd
Task 0xc0f4c600: 699 pages, 1 threads: pid 52: fairplayd.N94
Task 0xc0f4c3a0: 1410 pages, 9 threads: pid 53: dataaccessd
Task 0xc0f4ba20: 425 pages, 4 threads: pid 57: awdd
Task 0xc0f4b300: 458 pages, 5 threads: pid 60: apsd
Task 0xc0f4b0a0: 437 pages, 2 threads: pid 61: aggregated