Why you cant live without Google Talk? There are a lot lives out there living without Gtalk, like me. I use Skype professionally and Yahoo Messenger personally.
Nothing out beats Skype and Messenger in this field.
I even has dumped the Google mail for the new Outlook, pretty impressive mail service from MS. Now the Google products that I use day today are; my android phone and Google Chrome. Once Windows Phone 8 is out, i'll say bye-bye to my android. Finally only Chrome exists, which is good and I might continue to use it, making chrome the only product that I use.
So my point is, even a Google outage wont affect my life AT ALL!