Tidbits tries to find out. My answer is “not yet.”
You can do a LOT with Pixelmator, but every time I use it I miss Photoshop’s Smart Objects.
A Smart Object is a way that Photoshop can place another graphic file into a photoshop document and it always looks great because it is being drawn from the source file. Pixelmator doesn’t do that. If you place a high res file, like a logo, in a Photoshop document as a smart object and resize it a bunch of times it always looks great. Try that in a Pixelmator document and resize it down, just once, and it looks blurry and grainy.