Date: 27-May-2011
Actually I was looking for reviews on net before buying this lens but it is too early to get, so I took a bold decision to go for it and got it yesterday.
Today I got some time to test it and want to share a quick view on it so that it will be useful for others who are considering this on a DX body.
f/1.8 – Very Sharp with flash for portraits with Creamiest Background I have seen ever.
Without flash on tripod with timer – Center is very sharp and corners are very soft because of its large aperture 1.8
f/8 – Sharpest Edge to Edge (without flash on tripod with timer).
f/4 – Corners are average (without flash on tripod with timer).
f/5.6 – Corners are good (without flash on tripod with timer).
Overall, at all apertures, the Bokeh is very smooth and pleasant.
Also the focus is fast.
So if considering for low light (In my lighting conditions f/1.8 is roughly at 1/15 sec equals to f/8 at 1 sec) for portraits, I don’t think people will be disappointed at f/1.8 on DX.
Cons – 7 Blade aperture, you may see some circles (very few) in the bokeh
Sample Photos – Shot with timer at ISO 100, placing the camera on bed 
This may not be adequate to see the edge sharpness as the subject posted here is different but will give the idea on BG.
After spending little more time with this lens on DX, I feel
Best for
1. Portraits
A. Outdoor from f/1.8 to f/2.2
With this aperture, one can achieve shutter speed around 1/3000 to 1/4000 in morning low light itself.
The BG will be too smooth, creamy.
Face detection will not help too much in this case.
Only caution is to make sure the subjects focus plane is uniform across the frame,
otherwise most of things will be out of focus.
B. Indoor from f/1.8 with Flash it will be super sharp.
Face detection will help little more here.
so the most of area will be in good DOF and rest especially BG will be creamy.
Good for
2. Flowers
A. From f/2.2 to 2.8 for close shots with less DOF and good BG
B. From f/4 to 5.6 for super sharp corner to corner details with little compromise in BG.
Better avoid f/1.8 to f/2.2 for very narrow DOF.
3. Wild life
Never use it, AF will not be accurate and VR is not there, and 75mm will be most of the times too less other than Mammals with habitat probably.
Yes you will see that you are missing VR in continuous shooting mostly 100% shots are useless.
I would have had a better shot with 70-300mm VR in the below shot, where the subject is too close.
Ewen after having little challenge with light as it was raining heavily but this was not the results which I was expecting.
Only below one with heavy crop is atleast not completely shaken out
4. Landscapes
Can try with at f/8 to get edge to edge super sharp shots with good color and contrast in good light or mounting on tripod.
Will post some samples in this category in a year or two
Thanks for your time,
Sravan