I have a suggestion.

So I like that you can right click on an empty tile to erase other tiles on the canvas, the same way that you can right click on any tile to place it again.
Do you think you could implement the same effect for the pen tool?  I have the habit of right clicking on an empty spot to gain it's 'empty properties' like you would right click on another pixel to sample its color.

Oh, and once again, good work. Great program. 

Cool an update.

Zoom works great now.

Got to second Poli about being able to colour pick transparent. It took me a while to figure out why the colour picker wasn't working as I expected.

GUI nitpicks:
Palette panel column count looks to be fixed at 12. Can be clipped is the panel width is reduced. It'd be nice if a fixed column count was configurable per project to best suit the chosen palette as well as an option to fit panel width. Failing that a fixed value of 16 would be nicer than 12 as many palettes are built around power of 2 length ramps.
Tool settings for pen tool, brush size and brush shape (brush construction related) are separated by line style (stroke related). This is the kind of thing that bugs me.
On-canvas brush preview draws over the top of the tile grid lines.
It'd be cool if there was an option for tile indices to show when using tile-oriented tools but remain hidden when using pixel-oriented tools. The button in the tile draw tool options kind of suggests this.

Small bug:
If you toggle the tile indices flag with the hot key the menu entry doesn't reflect the current state of the flag.

Thanks

Say, is there a way to remove or set the undo limitation?  I'd really like to be able to undo all the way to the opening of the file, if possible.
Sometimes I end up wanting to see how something looks and 50 clicks later, find I've gone on a bit too far.

You've got my support!

I'm a newbie, so if any of you other guys have some good tutorials or anything to work with, no matter how simple, I'd be thrilled to do them.

Is there a way to make an animation by importing several gif frames made outside of Pyxel Edit? Everything's drawn already, just need to place each frame.

Also, it would be really helpful if you could implement an option for different frame rates per frame. With this feature I could replace my current animating software with yours. Thanks!

Booted into windows and tried it and the lag between zoom levels isn't so noticable, so it's probably just Wine.
With exponential zoom levels it'd probably be tolerable.

Nice to see it's got docking panels now.

The slow animated zoom is really horrible.  I want to zoom in on an area by ticking the mouse wheel up 3 times and be immediately zoomed in 8x. I want to be able to instantly zoom in and out to any desired zoom level. I don't want to be furiously spinning the mouse wheel for a minute.

The palette editing workflow needs a lot of work. I can't find any way to merge colours, or to manually reorder colours. Opening up the colour selector and changing the colour doesn't change the palette entry, awkwardly need a special duplicate colour selector from the menu. The current tool colour swatches are right over the opposite side of the screen from the palette so a lot of travel for colour work.

Is there no repeating tile view/editing for working on seamless tiles? This seems to me to be the single most natural feature for a tile-oriented editor.