I'm Erwan from Flock. (Flock is a web browser that includes a blog editor among other features).
So I'm implementing support for b2evolution - or I'm fixing it, because we support the Metaweblog/MovableType API.
But for mt.getCategoryList and mt.setPostCategory, while the spec (and other blogging platforms) is using "categoryId", b2evolution is using "categoryID".
For getCategoryList it's easy to workaround because I can look what I have in the answer (categoryId or categoryID) but for setPostCategory I have to know whether I'm on a b2evo blog before sending the XML-RPC query, so it's more difficult.
Is there any chance to get that fixed in a next version of b2evo? I imagine it would fix compatibility with other blogging tools as well.