I'm sure if the demand is there, then they will dedicate more acreage. It could be that the 2011 crop is all but spoken for, but if they can sell more in 2012, and demand props up the prices, you better believe someone will find more space to grow more.
This is not necessarily true, I don't think. If there is more money in selling very large quantities to a big company for a premium because it will not be available to anyone else (IE, signature hop), don't think they'll sell to the little man for less.
I wish I could think better of corporations, but in the end they'll do whatever brings them the most profit financially, not what brings the most people the best hops.