Java is used on certain websites.
Facebook's photo upload for example.
Also certain corporate logins are Java-based.

It is a blunder of the internet to have so widely adopted Java applets and integrated Flash.

On the "desktop" side, there are bloated programs such as Azureus/Vuze.

openjdk is not acceptable substitution for Sun's jdk. Most embedded java applets such as facebook's simply won't load at all. It's about as useful as having Flash 9, when the website wants Flash 10.