BTW, I just wanted to say a few words on the topic of "backwards compatibility" for a minute.
It was said (back in the SNES days) that Nintendo had known full well about the limited lifespans of console generations, and about the need for a "generation hop", from one console to the next (something they pioneered with the SNES). It was also said that they understood the concept of "backwards compatibility".
Between one console and the next, there's a sharp downward drop (as one console dies), followed by a slow upward climb (as the next one takes off). If you try to compress the timeframe of that gap, you risk killing the older console abruptly, or choking the life out of the newer one.
But with backwards compatibility you create a link between the two. It rounds out the sharpest part of the drop. Games for the older console keep selling, because developers know it's still "safe" to make them. The newer console has an advantage at launch, because the older still-playable games can help with the inevitable "launch drought" of software.
The "rounding" effect is only temporary (for the most part), but it applies to an extremely needy timeframe (the sharp drop), and any advantage a console gets early on seems to pay off in multiples when it really "takes off" ahead of schedule.
However, Nintendo deliberately sacrificed that advantage with the NES/SNES gap, because they felt that using an NES-compatible cart slot would've crippled the SNES's storage capabilities. Also, they didn't have to worry about Sega (being a newcomer) having the B/C advantage without them.
For the SNES/N64 leap, Nintendo knew that their storage situation was weak, and clearly couldn't afford to make it worse with SNES-compatibility. Also, their competitors (Saturn and PlayStation) were going with CD, so Nintendo again didn't have to worry about them having backwards compatibility. And yeah, it goes without saying here that sticking with carts was the biggest mistake Nintendo ever made. They knew that carts were weak. And if they had looked just one move ahead, they would've seen that they were literally handing their competitors the known advantage that they "weren't worrying about", with no possible way to level the field.
With the Dreamcast, Sega didn't have Saturn-compatibility. Because... they're Sega. What did you expect? Sony did have it. Sony got the "rounding effect". The PSone has been deified for it's success. The PS2 had a spectacular launch, even though it's games were sucky and few. Nintendo didn't have it with the GameCube. Because they went with carts for the N64.
Nintendo did pioneer backwards compatibility with it's entire GameBoy line, and the results taught the entire world how it's done.
BTW, it's also interesting to note that Nintendo appears to have successfully compressed the timeframe of the console gap between the GBA and the DS, overlapping the two lines, in order to take away the "timing" advantage of the PSP, through the "three pillars" strategy that nobody seems to be able to understand.