One change I am really disliking in OSX 10.7 is what they've done to iCal. It appears that it's no longer possible to get a view similar to GCal in which you have a small monthly calendar in the sidebar, and an arbitrary number of days displayed in the main body of the app by click-dragging across those days in the monthly calendar.
I frequently want to view 2-5 days at a time, rather than a full week (which causes events to pile up, when you have seven or eight calendars -- I have a couple of my own, Xta's, social group cals, etc) or a single day. I understand why this doesn't work on the iPhone, but in the iPad or desktop versions of this application, viewing a few days at a time is a Good Thing. When I'm trying to plan some kind of weekend socializing, I almost always want to be able to view Fri-Sun; and for thinking through how to schedule some weekday-specific errand around work, I frequently want to show just the weekdays.
Anybody know if I'm wrong about the loss of this feature? :-/