Marketing_Guy - 9:15 am on Jan 24, 2012 (gmt 0)

I predict we're gonna see a lot more feature sliders with just text, no images (which was what I was working on anyway, as it happens)

Be careful attempting something like this. A well known UK SEO agency got themselves banned from Google a few years ago for rotating text snippets via CSS. They were clearing doing it for SEO though but you can be sure they got that little nugget removed from their and their client's sites real quick! ;)

NO other changes in my niche except smaller (my size) competitors seem to have been hit even worse either on this change or at some point before it.

There could be a bunch of other things. I saw huge movements in one of my client's markets in Nov because a couple of big brand sites merged their content - the resulting improved website had a load of new rankings that pushed everyone else around. Or a mass wipe of backlinks. Or a number of other factors.

I really can't see Google punishing having an ad block in your sidebar - above the fold or otherwise. That's as fair practice as you can get. Might be worth looking deeper for other issues.