As I previously mentioned, I hit level 60 on my Barbarian and have been very slowly soloing Inferno. I am currently at the stage of Act 1 where I am heading towards a showdown with the Skeleton King. The funny thing is that all of the purple boss mobs are much much easier than the yellow mobs and the blue packs of rares.
I die a lot on Inferno and I use a lot of potions. I also use a few creative tactics. I mentioned previously kiting mobs to town if you are outside. One of the methods I have been using to deal with these rare and elite mobs inside Dungeons is by kiting them to the door. I beat on them until it looks like I am close to dying, then I go out the door. I heal up, pop back in, rinse and repeat. It takes a while, but it beats dying over and over again.
As far as other classes go, I have been quite enjoying them. I got my Monk to the beginning of Act 2 the other day with some friends, and have gotten my Demon Hunter to around level 11 or 12 with a couple of other friends. I really enjoy the different styles. I like healing and doing Kung Fu badassery on my monk. I like utterly destroying things and effectively kiting things on my Demon Hunter. I will probably work on getting all of the other classes to ACT 2 on normal. I have not played much of the Wizard or Witch Doctor, but thing that they will probably be pretty fun as well.
One thing for certain is that I will have plenty of gear for leveling.