Fellow designer Fernando Lins pointed out this link to a website that grabbed my attention.
Naked Light, as previewed, promises to be a fully resolution-independent image editor with all the powerful features a designer might need. I won’t be making my judgement until I have actually used the application (the public beta will be due in a day and 10 hours, at the moment of writing) but it seems promising, going from the website;
Naked light throws away antiquated concepts like pixels; layers; 8-bit color; and destructive, non-re-editable filters and operations. Instead, compositions in Naked light represent a sort of Platonic ideal—with infinite resolution, an astounding 590 quintillion colors, and perpetually re-editable nodes.
Hopefully, this will help alleviate the high hopes users had for a Photoshop replacement in Pixelmator, which apparently failed to deliver.