Samsung released the firmware for Fit a week back. Though it is available in Samfirmware.com, there are not detailed.I found another link and it was very useful.
http://droidangel.blogspot.com/2011/06/procedure-how-to-flash-installupgrade.html The next step for me is to work on moving apps to SD. Though the free App2Sd works, it is not working for memory consuming apps like gmail, maps, facebook etc. To do this we have to root the phone. Unfortunately none of the apps like Z4root, Androot worked except for the following link.
Typically, the next step is to partition your SD card using ROM Manager and then install S2E
BUT, S2E works only on cynagenmod phones.
There is another way to do it after installing SDK. Follow the link
I am able to move most of the apps to SD
Enjoy.....