.co isn't going to be the next buyout. .biz has already destroyed .co. When it comes to numerics, it's back to the basics with the original extensions that started it all, i.e. .com, .net, .org, .info and .biz. I don't believe .org and .us will do anything in numerics. It will probably only be .com, .net, .biz and .info.
I'm ify on .biz for the long haul. Patterns and appearance is everything in numerics, and .info seems to have the right look.
It is true that .info is only $2.99 to register at Godaddy right now. I like to get in before the Chinese and before the registrars jack up the price. Nothing wrong with early entry.
Like I said, numerics have taken over all the basic extensions one by one like a wall of water. .com... and then .net, and then .org, and then .biz, and .info it's beginning to hit. Foolish to think .info won't be next. I again think it will rapidly overtake .biz and .org and will begin to challenge .net.