Seems like the Dash dev disagrees with the icon author on where the line between "inspiration" and "plagiarism" lies. It doesn't help that there's a language barrier between the icon author and Dash developer.
But sadly it seems like this issue hasn't been rectified, but has just been forgotten about. I only found out about this after I'd bought a license; I'm posting this here in case someone else finds it relevant to their purchasing decisions.
I'm not familiar with the controversy besides what you posted, but my take away is that icon dev has some talent. The bookcase D is clever and well done, at least at that size.
In the link for the alternative icon, the icon designer has declined to enter any new discussions, as he felt "insulted" with the Dash developer's reactions on Twitter. He feels any more discussion is "a waste of time."
At any rate, I wish we non-Mac users had something like Dash.
In the interests of quoting the full context rather than just a few words, here's what he said in full:
"Dear The Great Developer of "Dash.app".
I do not ask you anymore.
I do not say anything about your icon.
It's a waste of time.
But I am vindictive.
Conversely, I inspired from your icon.
This is the way of my protest.
This time, you do not plagiarize this my icon, please.
Sayonara さよなら."
It seems the designer is Japanese, so there might be a language/cultural barrier too, but for what it's worth I think I would feel insulted by the Dash developer's reactions too!
Edit: so the old Dash icon was a free icon from http://www.yootheme.com/icons/freebies (the cat one). Recently this icon was replaced with a custom one, which makes sense, except the new Dash icon seems to be heavily "inspired" by somebody else's work -- http://dribbble.com/shots/913643-Chrome-replacement-icon
See the comparison here: http://twitpic.com/ciu8a7
Relevant tweets:
[Dash dev]
https://twitter.com/kapeli/status/328037766166368256
https://twitter.com/kapeli/status/328112260805451779
[Icon designer]
https://twitter.com/wakaba_en/status/328075341618892800
Seems like the Dash dev disagrees with the icon author on where the line between "inspiration" and "plagiarism" lies. It doesn't help that there's a language barrier between the icon author and Dash developer.
Icon designer even proposed an alternative icon:
http://dribbble.com/shots/1046492-Dash-app-replacement-icon
But sadly it seems like this issue hasn't been rectified, but has just been forgotten about. I only found out about this after I'd bought a license; I'm posting this here in case someone else finds it relevant to their purchasing decisions.