Microsoft has released Office 2010 as a beta that you can use up to and including October 2010 (scheduled to be released in June 2010). You can download it as either 32 or 64 bit, although it seems the 64 bit download is a bit hidden since many buttons for downloading seem to lead to the default 32 bit download. If you follow the link at the Professional Plus site to 'Get It Now' you should be presented with links to both versions. At the moment Microsoft supports Chinese (Simplified), English, French, German, Japanese, Russian, and Spanish. If you are like me you just use the application in English, but then miss some of the proofing tools for, say, Japanese.
You can download language packs from the Microsoft Download Center. If you change the language to, say, Japanese you are presented with two download links at the bottom for the Japanese language pack. This language pack includes user interface changes for Japanese as well as proofing tools, OCR support, and fonts.
Once the pack is downloaded just run it and you can customize want you want to install. Since I am not interested in the UI aspects of the pack, I selected the top part and toggled selection for all to not install. Then for the entries <span lang="ja">国際フォント</span> (international fonts) and <span lang="ja">文章校正ツール</span> (proofing tools) I made sure to install everything. <span lang="ja">文章校正ツール</span> includes both <span lang="ja">日本語用校正ツール</span> and <span lang="ja">英語用校正ツール</span> and I guess you can most likely skip <span lang="ja">英語用校正ツール</span> since it is already installed. <span lang="ja">国際フォント</span> includes <span lang="ja">標準フォント</span> (standards font), which I am guessing is related to JIS X standards for font encodings.
Basic Windows 7 has 134 fonts installed. A basic English Office 2010 install increases this to 198 fonts installed. Installing the Japanese language pack proofing tools with fonts brings this to 228 fonts installed.
If you press the expansion arrow at the bottom-right of the Home part of the ribbon (or press CTRL-D) you will get the Font dialog. If you select the Advanced tab you can turn on features such as OpenType ligatures. This will mean that with text such as 'fl' or 'ffi' certain parts of the letters will connect instead of showing white space between the letters. This is the same technique used in printed media such as books.
Update: Michael Hendry was kind enough to point out that I was mistaking <span lang="ja">標準</span> (standard/default) with <span lang="ja">基準</span> (standards/JIS/ISO).