Since the last keynote, where Apple announced iTunes 10, I've heard a lot of complaints about the vertical close buttons and the new icons.For the close buttons you should keep an eye on http://hints.macworld.com/, but at least I solved the problem of the ugly icon. Before updating, save the old icon by right-clicking on iTunes, and then on "Show package contents", then browse to Content/Resources and copy iTunes.icns somewhere safe. Now upgrade iTunes, and do the same thing in reverse, so you'll overwrite the new iTunes.icns. Below is a video and the original icon, in case you are to late to copy it yourself. You might need to start and stop iTunes a few times, or even reboot to se the "new" icon.
[update] Posterous doesn't like my icon. Download it from Dropbox instead: http://dl.dropbox.com/u/10094764/iTunes.icns
Also, about the control buttons: defaults write com.apple.iTunes full-window -1