Some really good points there from Puppychow.

I am thinking of starting Kara as well and I would only need to set up a few more accounts and then move some alts over even I do think Nixi set the bar far too high
However the only reason it would be remotely doable on my part, is soley to the fact that most of my chars outgear the instance.

With Wotlk things will change and I am sure we see more instances like MGT which I find a bit awkard to multibox and 10-man instances will be even more complex in nature.

Multi-boxing can be tremendous fun but it can really frustrating as well. Any fights which involve a lot of movement usually reduces the fun factor for me by a large margin.

We al l have to see how these raid instances in Woltk turn out but I doubt as well that multi-boxing them will be only be doable to a very small degree, esecially at the start due to being undergeared.