Hi,
I ran into a issue today by examining my campaign progress. For one of my Netherlands campaign, I see that a good chunk of traffic comes from English Language. In the past, I've used a Dutch Lander to go along with the English language. I changed the Dutch Landers to English Landers today and hopefully that gain more conversions. But, the issue is if I created a English Lander to promote in Netherlands, I don't have a English offer that goes along with it. How would you go about handling this?

Try testing a dutch offer first - the incoming traffic might well be bilingual. If that doesn't work you'll have to rethink, but I wouldn't assume - particularly in the Netherlands - that the audience only speaks one of the available languages.
You may want to cue your visitors into the fact that the offer will be in Dutch in your lander - spin it as a benefit, in that it's targeted specifically to Dutch people like them, or something similar.
Lot's of the Dutch guys speak perfect English.
I'm from Belgium (we also speak Dutch) and lots of my techie friends just install their operating systems with the English language as default.
That being said:
You can set
If the English language doesn't convert at all, you could test out redirecting this traffic to a service like YTZ.com
Anyhow: my guess is these are also Dutchies, so i'd serve them the Dutch lander.