Hi dipsol,
I've got a bilingual site w/o JoomFish. The main site is English and a subdomain is German, other languages may follow. The two databases are independent. Thus, my problem is getting sales and article status changes synchronized. The solutions I've seen up to now are based on sharing a common database, which won't work in my case, since the product descriptions for instance would have to be in one language or the other - or both...
So your component sounds like a good solution. Do you also synch the users? That's only a secondary concern and there are solutions for that on the JED. Feel free to PM me if you like.
Cheers,
Mike