Trillian Astra has finally, officially replaced Trillian 3. Users who experienced the Astra beta will find the final version to be similar, with the biggest change being the features that are limited to the paid Pro version. If you're new to Trillian Astra, this update makes the multi-protocol chat client competitive again.
The differences between the two versions are enumerated here; the short of it is that the extras are nice--but they're merely extras. You'll still get the improved performance, and support for mainstream services like Yahoo, AOL, Google, and ICQ. MySpaceIM is supported, and Skype is included, but it requires the program to be running before it can be accessed through Astra--just as Skype does with other multichat applications. It includes POP3 and IMAP account notifications rolled in alongside the Facebook and Web mail notices.
Perhaps most importantly, the Cerulean Studios team promises that Trillian Astra will be updated more frequently than Trillian 3 ever was, with regular maintenance patches.
Editor's note: There is a bug currently on the Download.com product page that indicates that the program is only available to buy. This is being worked on and should be fixed Monday. The program can be downloaded for free.