Apps like Things and OmniFocus are (still) the big contenders for your task-management dollars, but there are plenty of fresh ideas popping up from "smaller" developers. For example, ThinkingCode just released an exciting public beta: version 2 of Dejumble, their entry into the task manager market. We've been watching Dejumble since its early days, and it's always been a fairly unique player ... though not necessarily cut out for heavy-duty task management. Version 2 is taking a crack at changing that.
A streamlined interface is the base for a faster task entry system and great new search features. The tagging system is easily navigated with mouse clicks, and it works with smart folders (as you'd probably expect). In addition to projects and tags, tasks can have subtasks, so advanced organization is possible. It's looking impressive, for an early beta. While it's very usable right now, there's much to do before final release.
I corresponded with the developer last week, and got a list of features planned for implementation before 2.0 is officially released. Online sync, a more finely-tuned "Smart Bar" and other navigation improvements for large task lists, as well as further Mac integration (AppleScript, Automator, Services hotkey for note capture) are all promising. Also among the standout features in the roadmap is an iPhone (and, potentially, iPad) companion app, with iCal/over-the-air syncing. The iPhone app is, apparently, very close to being ready and should be available in time for the 2.0 desktop release.
The planned price for Dejumble 2.0 will be US$39, but it's a free upgrade for current customers and pre-orders will start soon at $20US. If you do grab the beta, be sure to stop by the support forum, get the latest news, and leave your feedback to help shape the final version!