I don't know what Atlassian will do with Trello, but their existing products are horrid.
We use JIRA (a bug tracker) and Confluence (a wiki). These suffer from
- poor use of screen space
- useless search
- crude and inconsistent text editing
- verbose, non-standard, and broken markdown
Atlassian products are built for shelf-appeal: they are designed to look good in sales demos, and to appeal the people who sign POs and checks: CEOs, VPs, and directors. But they don't actually work for the people who have to use them: programmers and first-line managers.
Atlassian puts their own bug database online. When you find a problem with Atlassian software you can search for it there. You will likely find that other people have found this problem before you, and opened tickets on it, which Atlassian has since closed, explaining either
- yes, it is broken, but fixing it would be hard, so we're not going to
- no, that's the way it is supposed to work, and we're not going to change it