Let me first thank you about your words and interest in Sitefinity!
The multilingual content functionality is not supported for a modules which are not generic content based. We have plans to rework the Lists module and the Forums module to become such. The only suggestion we could give you so far is to use the Generic Content module indeed.
The improvement of these module will be done in SItefinity 4.0, coming up shortly after Q1 2009. We have also plans to improve the Generic Content module - you would be able to create paired content items (just like in the Lists module).
Let us know if we could help you with something else.
All the best,
the Telerik team
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