We've done this for a variety of different reasons - basically Disqus works far better for us and seems to be much more widely adopted than Intense debate
All of our old comments have been successfully imported (I know, I'm shocked as well. We will remain silent about how much effort that took)
Apologies for anyone who prefers using intense debate but it is easy to use Disqus and sign up for it and it also seems to play nicely with other log-ons as well
Let us know if you're having any problems and we will pretend to be competent enough to fix them
