Iowa is only important because they are first.
They get their name repeated nightly by ever MSM there is.
For being first, they get to pay off big corn.
If not being first, no media would even buy gas in Iowa.
The only way I see Iowa being important is if two things both happen
1. Trump loses
2. He reacts very badly, causing him to lose support and/or the rest of the voters to gravitate toward Cruz.
Both unlikely, but possible I guess