Remind me. Don't the Catholic areas of Ukraine have strong ties to Poland?
Yes and no. The ones with the Polish ethnic population were the most Polish parts of Poland. But the ones with the Catholic Ukrainian population (primarily Uniates or Greek Catholics) were the hotbeds of Ukrainian nationalism - anti-Polish, pro-German/pro-Austrian, anti-Russian (in that order).
In the last generation Ukrainian nationalism of this variety spread from the west toward the center of Ukraine. Still the center being primarily Orthodox and so tied by the history and religion with Moscow remains less nationalistic. The east follow old Ukrainian way which is to be close to Russia.
Present rise of the pro-Western activists is an expression of the EU attraction. Many young Ukrainians dream about affluence of Western Europe and Soros related inspiration guides them into Serbia/Georgia "otpor" style "liberation".
The old guard derived from the Soviet time bureaucracy is in defensive and turmoil. It either tries to appease/please West (that is why despite the previous election promises Kuchma/Yanukovich did not restore the Russian language to the official position) or tries to lean on the new Russian leadership (Putin feels happy to oblige). But for the second option pro-Russian moods would have to be stronger (at least 2/3 of population instead of present 50-45%) and Soros style Western pressure weaker.
It is fascinating to watch the estetics/appearance/mechanics of the Serbia/Georgia method of elite replacement. Sleek methods of crowd psychology are being used, the excitement of the new beginnings, colorful logos, catchy inane slogans, gestures, hypnotic repetitions by the media. Truly something from the Brave New World or the foretaste of Antichrist.