We spent a lot of 2011 working on our server side, the main reason for this was to expand Dialogues to other phone clients outside of iOS.
Today we're excited to announce our first client to take advantage of this work... Dialogues for Windows Phone!
Dialogues for Windows Phone takes full advantage of the glorious Windows Phone metro styling to show you your messages, contacts and notifications at a glance.
We're integrated to Windows Phone Push Notifications to keep you up to date with messages. the same as Dialogues on iOS, if you turn on noticications, you'll see alerts when messages arrive and a badge on your start screen showing the number of unread messages and invites.

We've included the web link viewer we added in the iOS 2.3 release:

We've enhanced it to let you look at photos you receive full screen:

Dialogues is in the Windows Phone marketplace now, priced at $1.99 (or equivalent), with a free Trial version.
The great news for our existing users is that you can just log in to the trial version with your existing account and get the full experience.