Mac's going strong in 'that' market? It was the Ipod that saved Apple from financial ruin... anyone that uses a Mac should be slapped hard. Even guys I know in the desktop publishing world can't stand Mac's.
IBM weren't pulled because they were no good.. if you were old enough to remember the first PC's were IBM's. IBM was a giant in the computer world, they were the Microsoft of the day.. that is umm until Microsoft. IBM left the personal computer market because it was flooded and became a commodity. When I first started selling computers, we would sell IBM clones for $4000aud and that was around the 486DX66 speed. Now you'd get something like a Intel Quad Core 2.33ghz with about 8gb of ram, 24" monitor for around $2500. There simply is no money in selling hardware - seriously you'd have to be an absolute gimp to still be in that market. IBM realised this, so will Sony.