Button
- Desktop applications tend to have buttons, not links
- It's less important which standard you pick, than that you pick one.
Link
- Most of the time you want to confirm an action, not cancel it
- An extra choice requires extra thinking. Make that choice easier, not harder, to make correctly.
- A link is visually distinctive compared to a button, so should help the user make the right choice.
- Actions should be buttons, nonactions should be links {citation needed @ that comment - I couldn't find it}
I would, however, tip my hat to the button camp: I'd avoid labeling the link as "Cancel". The string "Cancel" is simply too deeply associated with desktop application dialog boxes' cancel button for a link with the same label not to cause an interrupt.
I'm now looking for alternative ways of expressing "Cancel", that don't sound awkward, and are short enough to act as an anchor
A related question is whether OK/Cancel or Cancel/OK is better. But that's an orthogonal issue, not for this post.