Once upon a time, a homepage was equated to a splash screen. A splash screen is directly borrowed from the desktop world, where it indicated loading of a heave application. However, it makes little sense in the web world. Typical splash screens carry heavy graphics with a link somewhere to enter the website. Along with the usability aspect, it also consumes visitor’s time.

As an analogy, splash screens like closed doors. In today’s open world, they’d better be open to welcome the visitors or bid them good bye.

For mult-lingual sites where you cannot predict the language of your visitor for sure, you will see often that a splash page is used to direct the use to the language of choice. That is the only use I stil see a lot.

Johan, I agree, sometimes the content to be displayed might depend on an option to be selected by the user. Something like in http://wikipedia.org/. However, if there is no such dependency the splash page is not useful.

Splash screens on the web certainly are annoying, to say the least. However, like Abhijit mentioned, they can be useful for displaying language selection options and are sometimes legally necessary for age verification (such as on alcohol-related sites).

Johan, like you said, a good homepage is a sort of an evolved splash page that should help visitors find the information they are looking for.