I installed not one, but two IM clients today. The first was MSN Messenger upgrade (7.5). Nothing radical here. Then I tried freshly baked Google Talk... Installation went smoothly and while installing, it detected existing installation of Gmail Notifier, unistalled it and replaced with new Google Talk client, also able to check my gmail. A fair trade... :)
Like the name suggests, Google Talk looks as it's primarily meant for voice conversation, although chatting works well too. Not much fancy stuff, basic iconography, but smileys are recognized and there are some neat text tricks like *emphasizing* text. The one thing that bugs me is the need to build another contact list. I'm using MSN Messenger, Skype, and now Google Talk, each with separate contact list. Also, currently Google Talk requires gmail account to use it, but that's going to change. All in all, a nice start.
On a side note: congratulations to Peter, for winning the C9 contest with this Outlook 2003 plugin! Way to go, man!