The current photoshop timeline is designed for the frame-by-frame editing of an existing video track, rather than the creation of animation from scratch.
I would like to request that the Animation Timeline in photoshop be made more like the Timeline in Adobe Flash. This would include things such as the ability to extend a keyframe over several frames, select frames, grab and move frames from one position/layer to another, and so on. Currently, all of these actions have to be performed through a clunky menu dive, a complex sequence of copying and pasting, or both. Also, frames are deleted if the framerate for the animation is changed.
I have worked with both Adobe Flash and Adobe Photoshop for several years. I use photoshop to create rough sketches and drawings, as rastor based graphics are very convenient for my creative process. I use flash to practice traditional animation. However, even with a tablet, vector-based drawing is not very good for things like building up transparency, brush softness, under-drawings, etc.
Also, if scrubbing the timeline using the arrow keys could be made as smooth as using the mouse, that would be a big help. This would allow Wacom Tablet users like myself to assign the arrow keys to the touch strips, rather than having to move the stylus when we scrub the timeline.