1. Very likely, I expect the graphics gap to be similar to PS2 - XBOX/GC, rather than like this gen
2. I expect the Wii to be a similar or silghtly higher price to the 3DS, so about £230-250 ($368-400), which isn't too bad
3. The 3DS suggests to a degree Nintendo will do that, by making downloads transferable to a new console and only 1 friend code. Other aspects of improving online play are still up in the air
4. This has started this gen, it will continue next gen and will accelerate faster if Nintendo's console is or is seen to be a success. It will never get the same level of 3rd party support as the other consoles, but I imagine it will be significantly better than the Wii's
5. I think the 'Super Wii' or whatever will be the JRPG home console of the 8th gen, but whether this will be apparent from launch I am unsure. If a mainline DQ game is announced for it early on, I can see many 3rd parties not wanting to miss an oppotunity to launch JRPGs on the 'Super Wii'.
