Also coming: a enterprise-specific version of the Google+ social-networking application.
Google plans to announce in the coming month or so several customer wins for Google Apps that exceed 100,000 users, according to Google Enterprise Vice President Amit Singh.
The customer wins will include corporations, government agencies and educational institutions, and are proof that cloud-hosted software is starting to become mainstream among organizations, Singh said.
"You'll see us announce in the next four to six weeks some very, very large customers, with hundreds of thousands of users on at one time, moving to Google Apps," he said in an interview.
Google launched Apps, a cloud-hosted collaboration and communication suite, in 2007 primarily for small businesses, but Google has been adding enterprise IT features to it regularly to attract CIOs and IT managers from large companies.
Although most collaboration and communication software remains on-premise, a market dominated by Microsoft and IBM, enterprises are increasingly more comfortable switching this type of software to the cloud.
This way, vendors host and maintain the software on their data centers, so customers don't have to buy hardware for it or spend time and effort managing and tuning the applications.
In addition, suites like Google Apps have been built from the ground for users to collaborate on documents, doing joint editing on files that are stored on a central server, instead of having to email files back and forth among members of the workgroup.
For Microsoft, the stakes are high in the coming year and beyond, as it seeks to hold on to the large user base of its communication and collaboration products like Exchange and SharePoint when they decide to switch to the cloud model.
Microsoft's cloud offering in communication and collaboration is Office 365, launched this summer as an answer to Google Apps and other similar products, whose vendors hope to lure customers away from Microsoft's on-premise products.
Reiterating comments made recently by other Google officials, Singh said that Google Apps customers can also expect to see a version of the Google+ social network designed for workplaces.
This enterprise version of Google+ is already in use internally at Google, where it has been a hit, increasing productivity within teams and improving the way people collaborate, Singh said.
"Our next stage is to bring this [version of Google+] to the enterprise so Google Apps customers can start to use the capabilities alongside Google Apps to connect all the dots," he said.
When the workplace version of Google+ becomes available, Google Apps will gain an enterprise social-networking component at a time when adoption of this software is expected to take off.
The market for enterprise social collaboration software, which offers Facebook and Twitter-like capabilities adapted for workplaces, will grow at a compound annual growth rate of 61 percent through 2016, a year in which the market for these products will reach US$6.4 billion, compared with $600 million last year, according to Forrester Research.
Companies like Jive Software, Socialtext, NewsGator, Yammer and Telligent have been providing this type of software for several years, while vendors like Microsoft, IBM, SAP and Salesforce.com have been adding this functionality to their broader business software as well.