TD bike related questions from a newbie.

[fifeandy]

Hi all,

I've been reading TD blogs and on these forums for a while but have never seen these particular questions answered.

1) From what I have read, Ti and Steel 29'ers seem to be by far the most popular frames.
    I can understand that Alu is a bit harsh on a road bike, but is this still a factor with fat tyres and 80/100mm front travel?
    And what about carbon?

2) Cyclocross bikes are now available with disc brakes does this make them a viable steed?

3) The tyre of choice has been a nano, however the blogs I have read suggest a race king is just as fast if a little less grippy.
    Conti are releasing 29'er race kings in black chilli for 2012 making them faster, grippier and more durable.  Will this make them the new top tyre choice?