Kahkonen is only useful here if it means Vitek is either going the other way or he's out long term. And they don't send Daws back when he returns, and he just becomes the odd man out.
I really don't believe in Kahkonen, as his career is pretty meh (inflated numbers behind Minnesota, who inflated everybody for a few years there), but he's been really good this year. So good that this is a career year for him, as he has better numbers behind the Sharks and this year's Sharks are probably the worst team he's ever played on. Probably even worse than last year's team, where he was absolutely brutal.
He would be a fine stop gap option for the remainder of the year, but only if the tandem we see down the stretch is Daws/Kahkonen and not Kahkonen/Vanecek.