The Chicago Sun Times is a leftwing wasteland that publishes diatribes from the likes of the anti-American faux-priest Andrew Greeley and race-baiting, affirmative action complainers like Mary Mitchell. Its mission is stated as such and its demise will not be mourned.
I give it twelve months before serious talk of merging with the Tribune. In two years, the Sun-Times will be thankfully dead and gone.
Tribune will survive if only because the news industry will still demand a midwest metropolitan bureau and representing newspaper. Newspapers will be published at a loss in stripped down format, if only to maintain presence, and expect profitability from online advertising.