Adium 1.1 is now available (released yesterday) and includes the following new abilities:

• You can arrange your tabs on any side of the message view, not just the bottom. Tabs are arranged vertically when you put them on the left or right edge of the window and horizontally when you put them on the top or bottom.
• Tabs handle overflow better by presenting a chevron (») menu, just like toolbars do.
• Tabs are now spring-loaded, so that if you drag something to a tab that isn’t active, it will activate, so that you can position the thing you’re dragging precisely within the inputline.
• You can have each tab display the number of unread messages, if any.

Adium 1.1 also offers the following:
• Prettier
• Faster
• Changes in the contact list, such as people coming online and going offline, animate smoothly.
• The contact list’s ability to hide like the Dock at the edge of the screen has been improved.
• A new type of AdiumXtra, the menu bar icon xtra, has been created to let you customize the appearance of Adiumy in your menu bar; you can download AdiumMenuBarIcons packs from AdiumXtras.com.
• Buzz on Yahoo! and nudge on MSN are now fully supported.
• AIM DirectConnect should be more reliable and less memory intensive; it is now automatically initiated as needed.
• You can now import accounts and chat transcripts from iChat.
• Adium now warns you if you run Adium from the disk image. This will especially benefit new Mac users who aren’t accustomed to working with disk images.
• Right-to-left text is handled property on MSN.

More info and download link here.