If you want to go back to the good old days you can disable hibernation and make your Mac sleep when you close the lid, just follow the instructions here:

http://www.macworld.com/weblogs/macosxhints/2006/10/sleepmode/index.php

If you want to disable waking up from opening the lid (quite useful if your lid has a weak latch), set the lidwake variable to "0"