I've added a bunch of new features into transmission-remote-dotnet. It now uses almost all the new rpc features in the 1.60 beta. Here's the ones I can remember

* samba integration (button to open torrent if you've shared your download dir)
* putty integration (i have a script it runs which unrars things)
* alternate speed limits
* port test feature
* enable and update blocklist
* a bunch of languages
* torrent priorities and seed limit ratios
* pieces graph

enjoy - http://code.google.com/p/transmission-remote-dotnet/

Alan
(transmission-remote-dotnet maintainer)