A quote from the posting on the developers blog:
I have just received an e-mail from Google that Transdroid, both the free and donate version, have been pulled form the Android Market. This is due to apparent violations in the content policies of publishing in the Android Market:
This is a notification that the application, Transdroid Torrent Manager with package ID org.transdroid has been removed from Android Market due to a violation of the Developer Content Policy. Please review the Content Policies and Business and Program Policies before you create or upload additional applications.
Note that Transdroid has been available for around 2 years on the Android Market. During this time there have been over 400.000 users who downloaded the app, who rated the app with a very high 4.6 stars average. Also, the Torrent Search module connecting to news feeds of sites that link to trackers by which media content can be obtained is still available.
The developer of the app has emailed Google to get a reasoning as to why the app was removed, but has gotten no response. Kok has stripped out the search functionality in the app in an effort to get the app reinstated in the Market, and it waiting to hear if this was the issue.
Could this be a sign of Google cracking down on apps that allow people to pirate content, even if they disclaimer that they do not host or link to said content? It will be interesting to see for sure, but the good news is that you can always get the .apk from a third party source if you desire. More info as it becomes available on this story.