Nikon has announced the update to the D300, by adding an "S", dual card slots (CF and SD) and 720p video and more speed to give us the D300s. The most important thing for manufacturers and underwater shooters alike is that there is a slight change in the back. This is probably to accomodate the new video function and dual card slot:
D300s back

Old D300 back

D300s Specs:
Image Sensor FormatDX
Image Sensor TypeCMOS
Sensor Size 23.6 x 15.8mm
Total Pixels13.1 million
Effective Pixels12.3 million
Image Area (pixels)
DX-format
(L) 4,288x2,848
(M) 3,216x2,136
(S) 2,144x1,424
Top Continuous Shooting Speed at full resolution7 frames per second
Continuous Shooting Options
DX-format
CH: Up to 7 frames per second
CL: Up to 6 frames per second
LCD Monitor Size3 in. diagonal
LCD Monitor TypeSuper Density
LCD Monitor Resolution920,000 Dots
LCD Monitor Angle of View170-degree wide-viewing angle
LCD Monitor AdjustmentsBrightness, 7 levels
Shutter typeElectronically controlled vertical-travel focal-plane
Slowest Shutter Speed30 sec. in steps of 1/3,1/2,1 EV
Fastest Shutter Speed1/8000 sec. in steps of 1/3,1/2,1 EV
Bulb Shutter SettingYes
Mirror Lock UpYes
Lowest Standard ISO Sensitivity200 in steps of 1/3,1/2,1 EV
Highest Standard ISO Sensitivity3200 in steps of 1/3,1/2,1 EV
Expanded ISO Sensitivity Options
Lo-1 (ISO 100 equivalent) in steps of 1/3, 1/2, 1 EV
Hi-1 (ISO 6400 equivalent) in steps of 1/3, 1/2, 1 EV
Storage MediaCompactFlash© (Type I/II, compliant with UDMA), SD, SDHC
File FormatUncompressed 12/14-bit NEF (RAW)
Compressed 12/14-bit NEF (RAW, Lossless compressed): approx. 60-80 percent
JPEG: JPEG-baseline-compliant; can be selected from Size Priority and Optimal Quality
TIFF (RGB)
File SystemCompliant with DCF 2.0
DPOF
EXIF 2.21
Pict Bridge
Exposure ModesProgrammed Auto (P) with Flexible Program
Shutter-Priority Auto (S)
Aperture-Priority Auto (A)
Manual (M)
Exposure Metering System1,005-pixel RGB sensor 3D Color Matrix Metering II
Variable Center-weighted
Spot
Metering Range1) 0 to 20 EV (Matrix or center-weighted metering); 2) 2 to 20 EV (Spot metering) (ISO 100 equivalent, f/1.4 lens, at 20 degrees C/68 degrees F)
Exposure Meter CouplingCPU
AI
Exposure Compensation±5EV in increments of 1/3
1/2
1
Exposure LockYes
Exposure BracketingYes
2-9 frames, in increments of 1/3, 1/2, 2/3 or 1 EV
Shutter Release ModesContinuous low-speed [CL] mode; 1-7 frames-per-second
1) Single frame mode 2) Continuous low speed [CL] mode: 1 to 7 frames per second (note 1) 3) Continuous high-speed [CH] mode: 8 frames per second (note 1) , 7 frames per second (note 2) 4) LiveView [LV] mode 5) Quiet shutter-release [Q] 6) Self-timer mode 7) Mirror-up [Mup] mode Note 1. When using EH-5a/EH-5 AC Adapter or MB-D10 Multi-Power Battery Pack with batteries other than EN-EL3e Rechargeable Li-ion Battery Note 2. When using EN-EL3e Rechargeable Li-ion Battery (When shooting in Continuous-servo AF ©, Shutter-Priority Auto or Manual [M] exposure modes, at a shutter speed of 1/250 s or faster with other settings at default)
Movie ModesMovie with sound
HD 1280 x 720/24 fps VGA 640 x 424/24 fps QVGA 320 x 216/24 fps
Movie AudioBuilt-in microphone, monaural
Optional external stereo mini-pin jack (3.5mm diameter)
Microphone sensitivity can be adjusted
White Balance
Auto (TTL white balance with 1,005-pixel RGB sensor) Seven manual modes with fine-tuning; Sun Shade Fluorescent Incandescent Flash Preset Fine Tune by Kelvin Color temperature setting
White Balance BracketingYes, 2 to 9 exposures, in increments of 1, 2 or 3
On the low end, Nikon also simultaneously released the D3000. Sporting a 10.2 mp DX sensor, the camera comes with a kit 18-55VR lens:
