I have barely had time to get into Lion myself, which leaves me ill-prepared to tell anyone much about the workings of the operating system. Instead, I'll link you to three pieces by people well prepared to do so.
Here's a Medium-Sized Lion Review by Andy Ihnatko.
Here's a Large Lion Review by Developer Wayne Dixon.
Here's a Super-Sized Lion Review by John Siracusa.
And finally, just for fun, here's Apple's "Lion's Out" Press Release.