If you look at the specs side by side, there is nothing noteworthy.
The T3 looks like a remake of the T11 which never made it to the United States.
Spec comparison here:
http://www.dpreview.com/reviews/compare_post.asp?method=sidebyside&cameras=sony_dsct1%2Csony_dsct3%2Csony_dsct11&show=all
...
Hi...umm...i know the Sony DSC-T3 hasn't come out yet, but i was just looking for other people's opinions on whether its really worth the better screen and smaller profile, actually, i like the way the DSC-T1 looks, the T3 looks a little plain w/out the sliding cover...but thats just me, if its really that "wow" then i suppose its worth it, but i want to see what others think...and if its worth the wait and the extra 50$

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