Another thing nobody has mentioned. Contrary to myth, RAW *does not* bypass all in camera processing unless somebody knows a RAW converter that turns off AA and all that other nonsense than Nikon/Canon use too much. With JPEG, it's a lot more limiting to chew through AA softness an other sensor limitations because those sensor aberations get locked into the file format and can't be filtered out. With RAW, you can far better isolate a proper sharpening technique or tonal adjustment that doesn't bang heads with JPEG artifacts or over zealous AA.
The optical low pass filter, which is what I'm assuming you mean by AA, is a filter between the lens and sensor, and:
a ) is not nonesense
b ) is not electronic, not part of the camera processing, and not turn on or offable
Did you mean NR or noise reduction? Yes, sometimes that is applied to the raw data and can sometimes be over-zealous. But long exposure NR, where the same shot is taken twice, once for the picture and then once dark, is very appropriate to do on the RAW data as it's more of a calibration process to increase the accuracy of the data you collected on your image.
RAW is both uncompressed (usually, and even if compressed, less so than the JPEG, and compression on RAW can work a lot better than compression on a processed image) and un-matrixed. The matrixing process for colour balance and colour space intermingles the data from the red, green and blue elements of the sensor, and this can make it hard to do some image corrections. Then of course, a non-linearity is added to the data to make it perceptually pleasing. You cannot correctly matrix on none-linear data, so again, it would be very hard to "undo" this to get back to the linear data to re-do or change the matrixing.
Some image processing and compositing works much nicer in linear light than in a gamma space, and these techniques are more commonly used in the motion picture effects industry. I for one, would like to see and be able to work with image data in Photoshop say, in linear light, but through an optional viewing LUT to give me a perceptually nice image to see, if needed.