I believe that SME's are going to become much more important in the world economy in the coming decades. Firstly, the youth today are a lot more demanding of themselves in relation to their careers, and are not happy to settle for a post in which they are unhappy. Many of them are seeking happiness as a first criteria.
Secondly, and possibly on a larger scale is the "Baby Boomer Effect". The people of this generation are beginning to hit retirement age. Due to the size of this group, many businesses will need to continue accessing their services, not as employees, but rather as consultants. In the USA today, 70% of all SME businesses are single employee consulting type businesses. This is a large number, when we take into account the number of SMEs in most countries is 90+% of all businesses. In short big business will experience large skills shortages, which will lead to them having to make use of more consultants who will be SME based.
There are also those people who are no longer prepared to be part of the rat race. They now work fewer days and live more remotely. They commute to work and then retire back to the real jungle, and away from the concrete jungles they work in. So I see the SME becoming that much more important in the future in the global economy.