Thoughts of combining Google services and Gears seems to be quite popular these days, however only one service so far (Google Reader) officially provides offline capabilities. Hints of offline support for Gmail surfaced last month after a Google translator pointed out a telling phrase he was asked to translate.
Type the following piece of text into your address bar in your browser while using Google Calendar for the proof:
If you look through the source code, references to Gears are scattered everywhere. After Google Calendar and Gmail both get offline support, maybe we should expect the same for Google Docs?