This is largely down to the change of icons, but the invitations in your inbox are now harder to spot than before.
For the normal user this might not be an issue, but our PAs with multiple managers that they're managing their calendars and emails for are finding they're missing invites to meetings so their managers don't end up going to the meetings they should do.
So, either change the icons (again!) to make them a LOT more obvious, or maybe do something with the invitation entries in an inbox.
I'm probably going to customise our mail template to shade meeting invitations, but I shouldn't need to do this