True if everybody has access to strong AI. I doubt that is the way it will play out. At least at the beginning. Whomever invents it first will probably hoard it for themselves as an advantage against everybody else. The technology will eventually spread to everybody else but by that time our economy will probably have adapted.

You're a little unclear as to why it's called the singularity. It means a point so drastically different that we cannot predict what the world will look like after it happens. However, should a planet still exist on the day after this occurs, you can pretty much guarantee that the company that controls this technology will make Apple, Google, and Microsoft look like technological infants. Well, unless it is Google, which seems to be the play they are making by hiring RK.

Also, World of Warcraft is virtualized, and everything in that game is potentially infinitely abundant. And yet, it still seems to pull in billions. So...

Yes, but my point is essentially that talking about profits in a post singularity world is probably as sensible as talking about Mao as CEO of China. After the singularity we will likely have a different socio-economic system and profits will probably be something like a noble rank is today.