Nikon d90 vs d7000

Sensor
The D7000 has a new sensor. It has a higher resolution (16.2MP) compared to the D90 (12.3MP). This will help photo editing needs of hard core photographers. The more resolution the more freedom you get when cropping images. Everyone knows the importance of editing their images in photo editing software. Adobe Lightroom 3, can really help improving the picture, especially if you shoot RAW.

ISO
There is a difference in the ISO range between the D7000 and the D90. The Nikon D7000 allows shooting in ISO 100 up to 6400, whether the D90 native ISO starts from 200 up to 3200. Both cameras have an extended mode. The D7000 can climb up to 25600, whether the D90 goes up to ISO 6400.

I see the ISO 25600 an advantage for some photographers. Even so, I rather stay with the D90 and spend my money on a faster lens, then upgrading to the Nikon D7000 alone. Having a fast optical stabilized lens can really helps sometimes. Of course the VR won't help you out much when the subject is moving, but in many cases, it is very helpful. If you tend to shoot with a telephoto lens without a VR, you should probably think of spending your money on a better lens, rather then upgrading. Overall, I think the better ISO sensitivity is an advantage for both enthusiast and professional photographers.

SDXC Support
SDXC is the next generation memory cards, features higher capacity and fast Read/Write speeds. Furthermore, with SDXC card you get higher performance when transferring images to your computer. According to my knowledge, the Nikon D90 doesn't support SDXC memory cards, only up to SDHC. Maybe it will be supported in the next firmware, I don't know. So as far as I know, the D7000 supports SDXC and the D90 does not (correct me if I am wrong).

Dual Memory Cards Slot
The Nikon D7000 comes with a dual memory card slot. Yes, you can use two SD/SDHC/SDXC cards together in-camera. It means more storage, without the need to insert a new card. If you shoot JPEG+RAW, this extra slot will help you separate RAW files from JPEG files. Furthermore, You can use the extra card for backup. Even so, the main advantage of having another card is probably for shooting HD videos. If you leave the battery life aside, having a large memory capacity, means longer HD videos. This is even more important if you shoot videos on in 1080p Full HD, which the D7000 supports.

Having an extra memory card slot is a great advantage. Of course you can live without it, but if you mainly shoot RAW or love capturing 1080p HD movies, this is a very important feature for you.

1080p HD Videos (up to 20min)
Nikon D7000 is capable of shooting 720p and 1080p HD videos. The Nikon D90 only features 720p videos. 1080p will be a standard on future Nikon DSLR cameras from this day forwards. Even so, when comparing the D90 vs. the D7000, the D7000 has certainly has an advantage of having both 720p and 1080p. This advantage will probably be more important for photographers who intend to take advantage of that feature. There are photographers who don't really care about 1080p or the HD video feature.

1/8000 sec Shutter Speed & 6fps Burst
Having faster shutter speeds is certainly an advantage for sports photographers. Pack it together with 6 fps vs. Nikon D90 4.5 fps, and you get a better sports photography DSLR. For many sports photographers, this feature alone worth upgrading from the Nikon D90. Nikon has also employed a brand new 39-point AF system and a new 2,016 pixel RGB 3D Matrix Metering System. Taking all of those variables into consideration, if I was a sports photographer, I would most definitely think about upgrading to the D7000.

Upgrade? - It Depends
Other improvements include a 100% coverage Pentaprism viewfinder, compared to the D90 96% coverage. The D7000 is a bit heavier (~80g) than the D90. The D7000 employs Nikon's EXPEED 2 imaging processor, Active D-Lighting and magnesium alloy body. Overall, the Nikon D7000 presents a new landmark for Nikon. It has raised the bar again, and really made the competition very interesting.

Whether you should upgrade to the Nikon D7000 from the D90, it is all up to you. You should carefully consider the advantages by going through the specs. If you find that there is an important feature that you find on the Nikon D7000 and not on the D90, maybe it will worth the upgrade. Even so, I think that before making a decision, you should ask yourself, whether you should buy a new better lens or spend your money on the D7000. It is a great DSLR, that I am sure that will satisfy the most enthusiast photographer.