iOS 7 Language Specs Published

It looks to be the same as for iOS 6 except for the addition of keyboard and dictionary support for Tamil, English (Canadian), and English (Australian).  Although not mentioned in the specs, I understand Chinese/Pinyin includes a new "10 key" option, which is something Chinese users have long wanted.

Also not mentioned are the new reference dictionaries:  Chinese-English, Korean, Korean-English, Italian, Dutch (added to the English, German, French, Spanish, Japanese, and Japanese-English already available earlier).

Scripts where iOS 7 has font support but no keyboard are Armenian, Bengali, Canadian Aboriginal, Georgian, Gujarati, Gurmukhi, Kannada, Lao, Malayalam, Oriya, Sinhala, Telugu, Yi.

Update 9/24/13:  The 10-key Chinese IM is so far only available in China.  A full list of keyboard layouts elsewhere can be found here.  One new one I noticed is an ABNT2 hardware layout for Portuguese, which will be welcome in Brazil.

Language Support

English (U.S.), English (UK), Chinese (Simplified), Chinese (Traditional), French, German, Italian, Japanese, Korean, Spanish, Arabic, Catalan, Croatian, Czech, Danish, Dutch, Finnish, Greek, Hebrew, Hungarian, Indonesian, Malay, Norwegian, Polish, Portuguese, Portuguese (Brazil), Romanian, Russian, Slovak, Swedish, Thai, Turkish, Ukrainian, Vietnamese

Keyboard Support

English (U.S.), English (Canadian), English (UK), English (Australian), Chinese - Simplified (Handwriting, Pinyin, Stroke), Chinese - Traditional (Handwriting, Pinyin, Zhuyin, Cangjie, Stroke), French, French (Canadian), French (Switzerland), German (Germany), German (Switzerland), Italian, Japanese (Romaji, Kana), Korean, Spanish, Arabic, Bulgarian, Catalan, Cherokee, Croatian, Czech, Danish, Dutch, Emoji, Estonian, Finnish, Flemish, Greek, Hawaiian, Hebrew, Hindi, Hungarian, Icelandic, Indonesian, Latvian, Lithuanian, Macedonian, Malay, Norwegian, Polish, Portuguese, Portuguese (Brazil), Romanian, Russian, Serbian (Cyrillic/Latin), Slovak, Swedish, Tamil, Thai, Tibetan, Turkish, Ukrainian, Vietnamese

Dictionary Support (enables predictive text and autocorrect)

English (U.S.), English (Canadian), English (UK), English (Australian), Chinese (Simplified), Chinese (Traditional), French, French (Canadian), French (Switzerland), German, Italian, Japanese (Romaji, Kana), Korean, Spanish, Arabic, Catalan, Cherokee, Croatian, Czech, Danish, Dutch, Estonian, Finnish, Flemish, Greek, Hawaiian, Hebrew, Hindi, Hungarian, Indonesian, Latvian, Lithuanian, Malay, Norwegian, Polish, Portuguese, Portuguese (Brazil), Romanian, Russian, Slovak, Swedish, Tamil, Thai, Turkish, Ukrainian, Vietnamese

Siri Languages

English (U.S., UK, Canada, Australia), Spanish (U.S., Mexico, Spain), French (France, Canada, Switzerland), German (Germany, Switzerland), Italian (Italy, Switzerland), Japanese, Korean, Mandarin (Mainland China, Taiwan), Cantonese (Hong Kong)