I love Trello. We use it as our editorial workflow board at Mashable (meaning it is where stories live from assignment (or sometimes conception) to the various editing/publishing phases. We use it to visually see what is publishing next, to see embargos or scheduled posts for different areas and more importantly, to see what everyone else is working on.
To me, that's the hallmark of a good tool: when it can be used in an industry it really wasn't designed for (publishing workflow) as if it was built for that purpose.
I think especially with management tools like Trello robustness is a huge factor, everyone seems to have their own series of cobbled together processes that kind of work for them, but with the feeling that maybe if they could digitise $PRODUCTIVE_METHOD it would be more productive. Trello's robustness to this helps make it really valuable.
Me, too. We started using it and it pretty much made software management as simple as managing a McDonalds. I simply put in orders for code into Trello and watch as the items move from left to right. Then, we just booted everyone who wasn't finishing during their shift so we're running lean and mean. I can't believe people used to think of writing software as a "craft," and it's frustrating to me that it took so long for people to realize it, but I guess this is kind of like the iPhone of software dev.