Part of me thinks the Ukrainian interim government should call Yanukovych's bluff, offer him a guarantee of safety and invite him back to Kiev, along with the $37Bn he plundered from the treasury (which he will doubtless claim he's keeping in order to prevent it falling into the hands of extremists), in order that he can stand in the early election he previously agreed to. That should smoke out the bugger's true intentions and embarrass the hell out of Putin.
It's ironic that Kiev was the seat of the Varangian Rus people - Viking in origin - who were the first Russians until their empire was overrun by the Mongols. What followed - the primacy of the Grand Duchy of Moscow - was a Rus principality that eventually became Tsarist Russia. Kiev can therefore be said to be the ancient heart of Russia.