I'm in the middle of reading materials about system analysis and design, in particular about Enterprise Application Integration. I took a break and checked out

I'm in the middle of reading materials about system analysis and design, in particular about Enterprise Application Integration. I took a break and checked out Reddit and HN. Stumbled upon this article and the GrooveShark AMA. I realized that these days some of the big websites are moving toward similar situation with that of a typical enterprise apps situation where there are different components/sub-systems written in different technologies. Is my assumption wrong? Seems like between Enterprise App (whatever Enterprise means) and these big Web 2.0 apps, the difference is only in the matter of the users; the former is geared toward businesses where the latter is leaning toward customers/end-users. The technology obstacles are rather similar.