Cocoa MySQL has always been my preferred tool for web development and web programming work. However, Sequel Pro version 0.9 has just been released at http://mjmedia.com.au/sequel-pro.html
This new app looks great, the new developers have cleaned up the interface to make it look more at home on Mac OS X 10.5 - and it runs extremely quickly on my 2.6Ghz MacBook Pro.
It doesn't look like any significant new features have been added, but it does seem more stable. I would recommend it to anyone working with MySQL databases on Mac OS X.