Here are the updated UFH files that work with new 2.3 update (K2, K2i and KDX) using the Georgia Font for Serif (the main reading font), and Droid for the Mono and Sans (including Bold and Italic - the font in the title bar and menus).
I haven't had a chance to test them on my Kindle but used
--ex and --sign when creating all three Install BINs using the new 0.6 Python script, and used the Uninstall BINs found on this forum, so they should work fine on the 2.3 without jailbreaking.
Please post your results, success or issues.
P.S. Some have been asking what characters this font includes (for international reading). I've attached a PDF file that shows all the characters.