Trillian developer Scott Werndorver posted some more details about the upcoming Trillian  version on the company blog.

There will be two new skins. As they are not ready yet, the published screenshots onyl show the old Whistler skin. A new feature will allow to send multiple files or complete folders. Trillian will put them into a zip file to transmit them as a single file. This allows to transfer multiple files, even if the protocol does not support this feature. Resuming file transfers is improved as well.

Right now, build 20 is used for internal testing. Once build 21 or 22 has been completed, the team of testers will extended.