I have no doubt that the first next-gen system i'll get will be the new nintendo console... but i'll buy an xbox 2 some time after.
i like nintendo very much, and most of the best games i played in my life were made by nintendo, or made for nintendo systems.
i love my xbox too, mainly because it offers me so many things that the gamecube doesn't, and it has great games too.
about playstation... well i just don't like it, and will never buy one. sure the ps2 has good games too, but the best ones are always ported to gamecube or xbox, most of the time with upgrades that makes them better than the ps2 version lol.
This is just my personal opinion...