One other thin about Lion's Notification. It took me a little while to discover I had to go to System Preferences->Notifications and set things up. It looks like if third party makes their program rightly then they will appear in notifications also.
I am really loving the iMessages App! Going from my iPhone, to my iPad or now Lion Mac i never miss a iMessage. To me this is going to eventually takes over from SMS. US Cell carriers are ripping us USA customers off on SMS since the being.
Mac Pro Dual 2.8 Quad (2nd gen), 14G Ram, Two DVD-RW Drives, OS X 10.8.3
2006 Mac Book Pro 2.16 (first Gen) OS X 10.7.4
2TB Time Capsule, 2 TB
32G iPhone 4S Black, iPad (3rd Gen) 32G Black