It should be available this week - this is how it'll work. You open your Messaging Pane in Outlook. Found on the top-right-hand corner and you should see a message asking if you'd like to connect your Google account. Choose to do so and it should happen seamlessly. Allow Microsoft to access your Google account and all your contacts are added. You can then use Outlook.com or SkyDrive and continue chatting with all your Google Pals. Clicking on a friends pic will bring up the chat box. This whole roll-out, should be completed this week and Outlook users' can use Google Talk from within their email.
The whole effort is being made to encourage people to come to Outlook.com and try it out. Microsoft seems to be stopping at nothing to attract more uses to Outlook. The service is actually quite good, but whether users will migrate to it en-mass is left to be seem. Do share your thoughts in the comments section below.
Source: Microsoft Blog.