1) Nope, I will buy a next gen console for it's next gen games. Note: I own all 3 current gen consoles, and that explains my opinion somewhat.
2) I think it's different because portable gaming doesn't have to be on the cutting edge of graphics, and games like Mario Golf and Tetris are still fun, despite using only 2 colours. For console games, the space saved, the enhanced loading times and enhanced graphics seem to be the biggest draw.
3) I would only pay $10 more for BC. I'd rather that an extra $20-90 that could be spent on BC be spent on more RAM, faster processors, or wireless technologies built in.