I love my Sony T1 ever since I bought it. If you read my reviews of the following editions of this marvel of miniature, you will find that improvements were incremental and cluttered actually with backsteps in certain functionality.
Out comes the Sony T9. Seemingly a step back from the T7, as it is thicker again (0.81 inch vs 0.63 inch for the T7 or same thickness as the T1) , or is it ?

Well I took the camera for a ride in Japan's electronic district Akihabara in Tokyo. I fell in love with the T9 instantly. First time I had some craving to replace my T1.
I would definitely buy this cam, if I had to go out today and make a decision. The optical image stabilizer is worth it's weight in gold.

So what is to like of the new features

6 MP resolution vs. 5.1 MP

Big deal, that is only 18% improvement in pixel count and won't be noticeable on an average print out or for that matter a large size print out. Don't expect the camera to give you 'sharper' pictures then the other cams from the T series. Tests have shown for this camera to resolve 1560 LpH a very typical value for a 5 MP class camera. The lens seems to limit the resolution
So, nothing earth shattering

640 ISO setting with low digital noise
Now that I like, gives you more range for low light conditions and reserve in speed. Don't quite buy the 'take action pictures sharp now' as low ISO settings are still a compromise.You will get more grainy picutres. But having reserves is what you want.

Antishake mechanism with moveable lens
You have jittery hands ? or like low light shooting ?
This is a major step forward. I tried shaking the camera while taking a picture. Impressive how sharp they still turned out. This feature is the killer feature in this camera. Sony packed an optical stabilizer in this package, which moves the lens to compensate for jitter. That's what you want, not an 'electronic' stabilizer that raises the ISO count to enable faster shutter speeds. With that you compromise for increased noise levels.

Large display with higher color range
Nice it does look markedly better

On screen histogram
Will show you the live histogram of the picture. Feature formerly found only in prosumer cameras. Now what is lacking is the ability to influence the picture easily in terms of exposure, so I consider this more a gimmick.

Single push button for animated slide shows
Nice, you push the button and the slide show will not just show one pic after another, but zoom them in, drop them in , fly them in. The drop in from the top is jerky though and not smooth. The show can be combined with MP3 music. Nice entertainment value

Big sliding lens cover:

Marked improvement from the T7. While the T7 is the thinnest cam of the line up, the lens cover was a bit flimsy. The T9 is solid

Body:
Comes in black or silver. I like the black one better
Drawback for both. Seems the body has a paint coverage, that is coming off the edges rather fast. Particularly on the front slider, you will see a 'worn' edge rather fast. Don't expect this cam to look pristine for long.It'll take the 'faded' used look rather fast. Won't impact the function, but Sony could have done better here

Gripes:
Body wears off fast
The flash is still meager and generates red eyes
Additional thickness ? (No gripe from me. I see reduced benefit in thickness reduction as the cam becomes difficult to handle).

Pro Duo memory sticks cheaper now, but still the most expensive in the industry.

You will need Sony's latest memory stick version. Read the pros and cons here:
http://www.epinions.com/content_168500629124

But now that prices have come down I'd rather recommend the Sandisk 1 GB memory stick Pro Duo.
See the verdict here:
http://www.epinions.com/content_175091125892

The previous Sony versions are:

T7 a tad thinner:

http://www.epinions.com/content_185297636996

T33 the queen of chrome and color: http://www.epinions.com/content_174292110980

T3 the base model:
http://www.epinions.com/content_166914657924

T1 , the original and my long time favorite:
http://www.epinions.com/content_167347654276

If you are a first time digital camera buyer, I recommend flipping through this baseline article:

http://www.epinions.com/content_3650658436

Trying to make up your mind whether to go small with the T9 or go midsize with the popular Sony P series?

http://www.epinions.com/content_122227887748

Tired of red eyes then you should take a serious look at this camera: (Won't fit your space budget though if you like the T9)

http://www.epinions.com/content_125044756100