Well this is good news to start a long bank holiday weekend! I was seriously worrying that Ukraine was teetering towards a messy Post-Soviet civil war.
Of course such an agreement relies on a certain amount of good will on all sides. Kiev has little incentive to decentralise or accommodate the desires of Easterners except to keep the Russians at bay while Putin is hardly the most straight-talking world leader (although he doesn't achieve the wide-ranging duplicity of certain American and British premiers).
However, behind the scenes there is going to be a huge amount of pressure to make a deal soon. Ukraine is a huge chunk of Europe and occupies a strategic position on the path of Russian gas and oil into the West. A civil war serves nobody's purposes even if it allows Russia to shows its nationalistic disapproval of the seeming unstoppable expansion of NATO and the EU into its territorial backyard.