A few features I would like:
(Keep in mind that I'm not telling you what to do, I really like this tool, but a few things are getting in the way of my workflow.)
1. Make the tile mode interactive. As it stands, when I am trying to make a seamless tile, I can't use a grid/guide to see where my texture really is, so if there is a problem along the seam, it is very annoying to have to swap between sides all the time.
2. Allow a (maybe optional) tile mode that repeats the tile across the entire work area. Again, It would be great for finding tiling issues, even if it is only in the preview area.
3. Remember the last export location. One time it spit me all the way to System32! WHY? Since when do people need to save ANYTHING there? Either remember the last location, or put a PATHS section in the preferences menu.
I haven't used Pixelorama for animation yet, but if development of my project continues seriously, I just might.