Tried looking for it but haven't really seen a lot of people with the same issue, at least not for updating to 2.5.
Anyway, exported my DB and then followed the upgrading instructions, both the official and other tips from users that had updated successfully.
Everything has worked like a charm, even though I'm updating to another domain which also needed me to import my old posts, comments, categories etc.
Now I see that after importing all the old posts, successfully I might add - all posts are uncategorized and hence posted into that category. Do I have to edit them manually?!