I personally do not believe we will see anything bigger than the A380 for many, many years, perhaps ever. Furthermore, I believe the A380 will have problems being a commercial success. The trend for the last 25 years has been towards smaller airplanes……2-300 seats is where the action is, IMHO. 767-787, A330-A350 sized airplanes are the future.

Those arguments can be opposed by other that have the same reasoning: Boeing sold more than 600 B747-400 in 20 years. Now the passenger volume has more than doubled, and Airbus would be totally happy to sell the same 600 A380. Note that when the B747-400 came out, it wasn’t purchased due to range any more. It was capacity.

Boeing does Airbus the favor of slowly scrapping the -8I project, cancellation can be expected within this year depending on overall market situation. Very unlikely they will ever restart it, so Airbus is the only one there.
Before an aircraft bigger than the B777-300ER get available, at least 10 years will pass. After the B787 Boeing must put its attention on the Single Aisle market, like Airbus.

And airlines get bigger. In a few years we’ll have three big airlines in Europe, probably only three network carriers in North America and no one knows how it develops in Asia.

In the end, many arguments can be said for or against the A380.