It is forecast that companies will get smaller not bigger. If you look at the number of people who work for IBM vs say Facebook. Many areas of business can work with less.
For example, in my company we have no IT department, all of our systems are in the Cloud. We are a Social business using social media, internally and externally which means we don't have a Marketing department. We spend no money on cold calling, cold email, advertising, as all our business goes through social. This reduces the number of people required in sales and marketing.
The risk? The key to this is that companies take an outside-in approach, rather than an inside-out approach.
Established companies of tomorrow will look more like their smaller, disruptive competitors of today. Why? Mainly because of massive change in competitive and consumer needs, in fact 60% of consumers in the United States say they find it easy to switch from one consumer goods brand to another. These dictate equally massive transformation of company operating models.