From what I can gather there’s a lot of work going on behind the scenes into trying new things, to see what works and what doesn’t. The only way to do that is to try it. Maybe the slider will be a roaring success, maybe it’ll be a complete misstep and be binned, maybe it’ll be tweaked so that it presents differently. Maybe it’ll turn into something else entirely, who knows.
Every time there’s any change there’s outrage because it’s slightly different, and there have been plenty of things tried and removed over the years (remember the short-lived inline hotlinking, for instance?). It’d be great if the forum could be free to use for everyone and be completely text-based with no other content other than the forum itself – and I get the impression that there’s a few people who will never be happy unless that’s the case – but the bottom line is that if they did that they’d have to shut up shop by the end of the week.
I’m sure no-one would be happier than Mark to have the site advert-free, and I know he’s looking into alternatives to reduce the reliance on them. But that involves changing things sometimes.