hi,
I need a functionality, that new users, when logged in, would see highlighted categories (in a sideblock), which have new items.

Does XOOPS have a articles/news/blog module with such functionality?

ps.: in addition it would be nice to have cats/topics with new comments marked as well.

The new item marking would be more significant than new comment.

If there's no such module, would it be hard to implement this?

I think most forums (at least phpBB) have similar feature, but there new topics are equivalent to simple replies/comments..