The single most annoying thing about the new defaults in OSX 10.7, aka "Lion" is one I nearly forgot because I almost immediately changed the default: The scroll bars are hidden by default.
Why is this important?
Because the scroll bars give you, with very little wasted space, two very, very critical pieces of information.
Their presence tells you that there is more to be seen, and the "footprint" of the scroll tab combines with it's position within the window tells you both how much of the total page you are seeing, and what your position is relative to the whole document/web page/whatever.
In the default mode, you may never realize that there is more to be seen.
In my opinion, this is the single most egregious mistake they made. Fortunately, it's also easily fixable. Go to your system preferences, and under the general preferences, select the option "Always" under "Show Scroll Bars." You won't lose much space on the screen, but you'll immediately know if there's more to see in any open window.
Insofar as the scrolling directions being changed - I actually like it now that I've grown used to it. Almost all of my computer work is on a laptop, with a trackpad front and center, and I spend little time on a mouse.