[Erwin]

Another reason why we do not want to release vB3 Beta hacks, and prefer to wait till at least vB3 RC.

A post by DJE on vB.com which explains it well:

in vb2, all the text is directly in the templates, and to translate the forum, you have to edit each and every template manually.

in vb3, the developpers thought it might be easier to develop a "language system". This system is pretty simple. In the admin CP of the forum, you'll have a bunch of words and phrases that you will be able to translate, without relation to where they appear on the forum (stuff such as "Edit", "View", "Send a P.M.", etc.) These tidbits of text will be used through all the templates, using php code. So if you translate "View" in the admin CP, it will translate it everywhere in the templates where the php code linked to "View" is.

but now there is a catch: since the style has not been developped yet for vb3, the old vb2 templates are still used for the beta, which means that they still contain all the text directly instead of the php code that works with the language system. editing those templates would be useless, as they will be modified for the gold release. However, translating the stuff in the "language system" in the admin CP is usefull, cause this stuff will be used in the final style. So you can start translating this stuff right away, and when the gold is released, all you will have to do is translate the new words/phrases added to the language system that were not added already.

Hope this helps you understand the difference between the language system and the templates

As you can see, the templates are still hardcoded in vB3 Beta, which uses the ugly template being used at vB.com. The "real" language system (which is revolutionary) will not truly be working until vB3 RC. At least that is my understanding. So don't be too quick to hack the Beta - best wait for RC.