In wat ways is nikon D90 superior to the nikon D5100?

I want to buy a professional or a semi-professional camera. So i came across nikon D90 mainly bcoz of its value for money and also many ppl told me about this cam as a very good semi-professional cam at a slightly low price. The D5100 is obviously an inferior cam to the D90 and also it costs less, but when i compared both the cams the differences were not very highlighting. So i want to know in wat ways is the D90 superior to the D5100

Built in auto-focus motor, depth of field preview, better handling/controls, larger viewfinder, pentaprism viewfinder.

The D5100 is much better though if video is going to feature for you and also being newer the sensor is slightly improved e.g. Slightly more colour depth and dynamic range.

The D5100 isn't inferior. It's got a better sensor and beats the excrement out of the D90 when it comes to video.
The D90 has a motor in the body which allows it to use any Nikon AF lens and it can control flashes remotely.

If you are using the camera just for taking 2D stills the D90 win.HAND DOWN!
If you are making movies and doing lots of cropping then choose the D5100

Megapixel count isn't everything. The $7, 000 Nikon D3s has a 12MegaPixel sensor and it is arguably the best DSLR you can buy, as it has better low-light capability and noise-free high-ISO capability of any camera as of date.

While the D90's 12MegaPixel sensor is not a full frame sensor as the D3s has, there's more to a camera than just how many MegaPixels it has. You will not notice much difference, if any between a 12Mp and 16Mp sensor.

The D5100 is an entry-level camera, while the D90 is an advanced amateur camera, and has features such as an internal focus motor, CLS remote commander capability, high speed flash synch up to 1/4000 sec, user definable and more flexible white balance controls that the D5100 lacks.

If you want video, perhaps the D5100 is a better choice, but if you desire the advanced options the D90 has, it would be a better choice.