Uninformed is a temporary condition, fixed more easily than ever.
Ignorant, on the other hand, is the dangerous situation where someone making a decision is uninformed and either doesn't know or doesn't care about his lack of knowledge.
The internet lets us become informed, if we only are willing to put in the time and the effort. That's new--the ability to easily and confidently look it up, learn about it, process it and publish to see if you got it right.
Alas, the internet also creates an environment where it's possible to feel just fine about being ignorant. It's easier than ever to live in a silo where we are surrounded by others who think it's just great to not know.
"Ignorant" used to be a fairly vague epithet, one that we often misused to describe someone who disagreed with us. Today, because it represents a choice, the intentional act of not-knowing, I think it carries a lot more weight.
The more I think about this, the more I'm aware of just how ignorant I've chosen to be. Not a happy thought, but a useful wake-up call.