If you are planning on going, you might want to consider making your room reservations now, if you can. There is a big broadcasters convention (90,000-100,000 attendees) that overlaps the first few days of the world cup. I was just looking at Embassay suites and they don’t have many rooms left. Hotels in Vegas usually charge for the first night on your credit card and you can cancel it if you find a better rate/hotel without charge (usually within 72 hours or less of your arrival date).
I am looking now for my room. Prices are high because of that convention.
Broadcasters convention: April 11-April 16.
World Cup: April 15-19.