A splash page can sometimes be used to help determine the language preference of your visitor, or help narrow down their geographical preference etc. but at a severe cost to your search engine optimization. This is because your homepage is the most powerful and indexed of all pages on your website.
A much better solution is to default to the most common language, or region for your website and allow users to quickly change to their preferred selection.
If you must use a splash page, be sure to include content links to all relevant areas of your website.