It seems to be getting harder and harder to classify motorcycles. Cruisers are not just cruisers any more. Increasingly, sport bikes are becoming specialized and tourers cover a broad spectrum.
Perhaps, we will reach a point where many motorcycles do not fit into any category, whatsoever. The lines become blurred so badly, that simple labels no longer work.
As manufacturers search for smaller and smaller niche markets, their bikes necessarily become hybrids. The Ducati Multistrada is an example of a bike that fits into no traditional category.
Indeed, as niche marketing becomes more important in the motorcycle industry, smaller manufacturers, or those that simply have the ability to react quickly to market changes may have an advantage. Yamaha comes to mind as a large manufacturer who seems to be able to fill a market niche quickly and effectively. The new MT-01 would be an example of a Yamaha motorcycle that fits no traditional category, but is nevertheless appealing to a significant number of buyers.
What does all this mean? Expect to see some interesting machines in the near future that depart from the traditional categories of motorcycles. A further blurring of the line between motorcycles and automatic transmission scooters will be a big part of this evolution.