After installing Leopard, I found the following totally new keyboards: Tibetan (3 options), Jawi, Kazakh, and Uighur. There is no Kurdish layout, although this language is mentioned as being supported in Apple's Leopard "new features" page.
Other new keyboards which add options to what was already available in Tiger are: Traditional Chinese Zhuyin, Vietnamese Unikey (4 options), Arabic PC, Russian PC, Persian QWERTY, Sami PC, Norwegian Sami PC, and Swedish Sami PC . Traditional Chinese Pinyin is reportedly a totally new version of what went by the same name in 10.4.
Here is the total list for Leopard (an asterix indicates multiple options): Arabic*, Azeri, Armenian*, Belgian, Brazilian, British, Bulgarian*, Byelorussian, Canadian French, Cherokee*, Chinese (simplified and traditional)*, Croatian, Czech*, Danish, Dari, Devanagari*, Dutch, English, Estonian, Faroese, Finnish*, French*, German, Greek (regular and polytonic), Gujarati*, Gurmurkhi (Punjabi)*, Hawaiian, Hebrew*, Hungarian, Icelandic, Inuktitut*, Irish*, Italian*, Japanese*, Jawi, Kazakh, Korean*, Latvian, Lithuanian, Macedonian, Maori, Nepali, Norwegian*, Pashto, Persian*, Polish*, Portuguese, Romanian, Russian*, Sami*, Serbian*, Slovak, Slovenian, Spanish*, Swedish*, Swiss (French and German), Tamil*, Thai*, Tibetan*, Turkish*, Uighur, Ukrainian, Uzbek, Vietnamese*, and Welsh. Plus Character Palette, Japanese Kana Palette, Keyboard Viewer, Dvorak*, US Extended, and Unicode Hex.