Filter Forge is much more than any other single Photoshop plugin; the point is that you can make your own unique filters to perform all kinds of tasks. While I haven’t used it in some time, I do remember thinking that this could be the only plugin you need for most every kind of ‘generative’ effect, meaning pixel-pushing and automated painting based on kernels and existing information. You won’t get noise reduction or print enhancing capabilities, so stick with Noise Ninja or BlowUp for those jobs. But textures, patterns, frames, and the like are all well within the realm of ‘cool stuff you can do’ with Filter Forge.
And if you’re on a Mac, the beta is free right now. Go. Run to her. Download and install her right away!