[kubrickslair]

Yes, the difference with Apple is illuminance. But I think they started it when they were much smaller, and it was meant to be promote word-of-mouth-ish promotion. Sure now that Macs are popular, it sucks to have too many illuminated logos being thrown in your face. I don't like that either. I too find it sad that too many children these day will think the Apple logo is synonymous with computing devices. At least in the earlier days there were many different logos from different companies.

Going back to ThinkPad, I think the difference was that it was a small logo on the corner. Consider having a big ThinkPad logo in the center, and how odd it may look to anybody who looks at the user. Probably why other manufacturers also do it.