I think it almost depends on the author and the particular sci-fi genre.......one example comes to mind after reading Max Brooks' novel World War Z. After reading it, I kept thinking to myself, 'where's all the character development' and at the same time, I kept thinking to myself, 'forget that; I can visualize the characters in my head, thus I don't need any "character development" to imagine who/what the characters were. There's also the question as to whether a particular work could be adapted for either the big screen or for television and whether that has any influence on an author as they're writing; if an author thinks for a moment that their work may be on the big screen or television, that could also influence how they write. As to the length of sci-fi novels these days...I go back to what I said at the beginning of this post; it depends on the author and the sci-fi genre that their work(or works) fall into(hard sci-fi, military sci-fi, apocalyptic/post-apocalyptic sci-fi, etc.).