It's already very easy to upgrade your wordpress using an FTP client but now wordpress has that cool upgrade feature where you don't even have to worry about that part anymore. I like the interface and how you can customize it to your own fancies too. By the time I get used to it I am sure there will be another update though. You can check out my blog post on my upgrade to Wordpress 2.7 here.
Who else likes the fact that you don't have to download plugins anymore, WordPress will just do it for you?
Yeah, just go to Plugins -> Add New and search for the plugin you want and it will do everything for you. I love it.