I got my hands onto a Curve 8300 with 4.3 OS!
I have the device for sale as well... but just in case anyone wants to see the screen shots and interested in checking out the new 4.3 OS, here you go:
I haven't been able to take all the screenshots yet..but here are some changes that I noticed
The device is on sale here:
http://www.blackberryforums.com/buy-...3-os-read.html