When composing messages, you should be able to access Gmail's new address book by clicking on "choose from contacts" link. Unlike the old way of adding contacts to a new email, you can now browse through your entire address book, choose your frequently mailed contacts, or use the search feature to add more people at a time. The address book includes all the users from your domain. The feature has already been available for a while in Google Video and Google Docs.
Google promises a completely new layout for the document management interface of Google Docs, but it's unclear if this will be available for everyone. "Soon we'll complete a visual overhaul of Docs & Spreadsheets that will make it much easier for users with dozens or even hundreds of documents to search, locate, and organize their documents."
Among other updates, you'll be able to add more gadgets to your start page, including the Google Talk Gadget.
More info: The update for Google Docs will be launched on June 27 for everyone (not just for Google Apps users). "We're going to launch a new Docs list -- a wish fulfilled for those of us who've wanted an easier way to organize and manage our documents and spreadsheets."