No, all of those consoles have hardware (in addition to the new, more powerful hardware) that let them run the previous generation games natively. There is no emulation involved.
What do you mean "depends"? It doesn't depend on anything, you cannot emulate hardware, that you don't have, without having hardware that is vastly superior to what you want to emulate, it's a physical impossibility.
The context is the same, when we talk about an "n-bit system" we are always referring to the word-size of the processor. At the time console producers only used that term as a marketing ploy, in fact no console or computer, even today, has a 128 bit architecture. Some have 128 bit components...
Which is bad for Nintendo, because they make money out of the games NOT the console. Right now they're selling the 3DS cheaper than what it's costing them to produce it, which means they're losing money per unit sold.
Yes it is. What do the following numbers have in common?
98, 400, 2520, 27910.
They increase by an exponent of 1.307 (approximately, this is just an example). Again, it seems a pretty exponential sequence to me.
Some GCN games are quite expensive, at least in europe. You can easily sell Tales of Symphonia, Fire emblem, Skies of Arcadia Legends, etc. For more than 30€. Most of the games will be very cheap though.