In reply to girlymonkey:
We've brought our kids up bilingual from the start and have always tried to buy or read the books in their original language, as sometimes in adults books the context and flow is lost in translation, although this does at times depend on the quality.
Julia Donaldson is one example, where all her stories are designed to flow, but having watched/listen/read the gruffalo film & books in both languages, it simply doesn't translate so well. But, this could be an adults perception, the kids may be less so, although the 7 yr old is now very fluent, grasping the details and quirks of both languages. We've all read books ourselves which because of the language style, grammar, punctuation etc. are simply painful to read and you feel like giving up after a few pages. I wouldn't want the kids to feel like that.
There are of course translations beyond your native tongue/s and we have a few, they aren't any better or worse than our usual translations and it wouldn't put us off buying them or encourage us too either, it simply adds to the variety of their collection, which is probably around 200-300 books.
Pictures, a little when they were younger, but less so now. They have little books they read themselves with pictures as if it's a new or different word, the picture might help them grasp the meaning and proper novels with practically zero pictures in which we read a chapter every bedtime for them, such as the books by Dahl, where you'll get a fussy pencil drawing once every 5 or 6 pages.
I don't think any of our books follow a traditional theme or specific nationality, which would put us off buying another that didn't fit the trend. But, I wouldn't buy one that was poorly translated and risk confusing their grammar etc.