iOS 6 Has New Reference Dictionaries

I have found that iOS 6 will download reference dictionaries for Spanish,  French and German if you hit the "define" item for a word in those languages.   This feature is buried in the release notes.  There is also a Chinese dictionary, as mentioned on Apple's "new feature" page.

OS X 10.8.2: New Language Features

In this update released Sept. 19, 2012, Apple has added a French module to Dictionary.app and added Mandarin, Cantonese, Spanish, Korean, Canadian English, Canadian French, and Italian to the language coverage of the Dictation feature.

iOS 6 Language Features Published

(The same as OS 5 except for Siri, I believe)

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 (UK), 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, Thai, Tibetan, Turkish, Ukrainian, Vietnamese

Dictionary Support (enables predictive text and autocorrect)

English (U.S.), English (UK), 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, 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)

New software keyboard layouts have been added for German, French, Turkish, Catalan, Arabic, and Icelandic.  A full list is at this page.

This page gives info on which iOS 6 features are available in which country:

http://www.apple.com/ios/feature-availability/

New Character Map App

Many users have been annoyed by Apple's deletion of the View = Glyph feature in the revised Character Viewer app of OS X 10.7 and later, which made it impossible to directly view and input the entire glyph catalog of individual fonts.   Ultra Character Map restores that capability:

http://www.x04studios.com/ultracharactermap.html

Unfortunately, for glyphs without Unicode code points, input is limited to a graphic of the glyph, rather than a normal "character".