"In the market for cameras with interchangeable lens, or single lens reflex cameras, Canon controlled 44.5 percent of the market, followed by Nikon with 29.8 percent and Sony with 11.9 percent, according to the data."
So for interchangeable lens cameras (includes mirrorless), Canon, Nikon, and Sony combined have 86.2% market share. That leaves 13.8% for M4/3 (Pana & Oly), Pentax, and anyone else who makes such cameras (leica with M9/8, Ricoh, Fuji, etc).
http://www.bloomberg.com/news/2011-04-15/sony-nikon-narrow-gap-to-canon-with-new...
"In the market for cameras with interchangeable lens, or single lens reflex cameras, Canon controlled 44.5 percent of the market, followed by Nikon with 29.8 percent and Sony with 11.9 percent, according to the data."
So for interchangeable lens cameras (includes mirrorless), Canon, Nikon, and Sony combined have 86.2% market share. That leaves 13.8% for M4/3 (Pana & Oly), Pentax, and anyone else who makes such cameras (leica with M9/8, Ricoh, Fuji, etc).