I'll add in my 2cent on splash page, both experience and from the articles i read.

Splash page does serve for its purpose back in the days of 56k modems or slower, and the plugin wars, remember bonzi buddy era? you can't imagine yourself downloading 999999 different plugins just to go into a site and enjoy the experience, luckily now, we had flash to top the wars and won.

now let's go back to the topic, imagine going into a site without a warning that it uses special plugin that normal fresh OS doesn't come in one package, and you get a big red 'X'. so what? what you going to do next? and the site is the only place you want to go?

There comes the splash page, where it acts as a information counter to tell you about what is the content is about inside, and to ask you to prepare the necessary plugin, for this instance, Shockwave Flash Player 8 or higher. Or back in the old days, they let you choose in between high-band or low-band site for slower connections. The reason we felt it's not necessary now because of auto detection or connection script or whatever

But since then we've seen so many abuse on it, that is so ignorant with putting splash page because it's fun. Well, that defeated the purpose of it at first. But of course now there's even more use of splash page to it, some people use it because they want it to act as a branding front page, a welcome door.