Operations Manager 2007 R2 from what I have seen and experienced looks more of a finished product (those who have worked with OpsMgr 2007 since its early beta days will know what I mean :-)). The console from my initial testing and from demos looks visibly faster, you now have access to the health explorer from the web console (yay!) and they have 'tweaked' notification . I suspect stability has also been further increased and the new major feature mentioned was the inclusion of cross platform monitoring.
Now before you become all excited please remember in order to upgrade for 'free' you must have bought licenses with Software Assurance, if not well I am afraid if you want these new features it will require new licenses....so will you upgrade? Are the features in R2 worthy of an upgrade? I would love to hear your thoughts.....