We have a number of applications that are now looking tired and a bit drab. Looking at the MS style fluent interface looks nice but seems (to me) to be more document based rather than task based.
Is there a nice 'modern' ui style that lends itself to task based applications?
Graphic style is pretty much independent of whether a UI is object-centered or task-centered. If you’re just looking to refresh the appearance, I don’t see why you can’t take some of the elements from MS’s examples and put them in your apps (e.g., various shades of one color, gradients and swoops, “soft” abstract icons, rounded corners). Check out MS’s own Inductive User Interface Guidelines for screen-shots of task-based apps that use some of these elements.
Alternatively, you could try to be original, rather than merely fashionable. Just a thought.
While you’re at it, take this opportunity to fix some usability problems or other functional weaknesses you’ve been observing over the years. If you don't give your users something practically better, they're going to associate the new style with making life difficult, rather than something exciting.