Well, they've been trying to replace Kournikova for a while... she is much hotter than Sharipova, whose face is nothing special. Her body (like many others on the WTA) is out of this world, and she's a very good player too.
Personally I don't like watching women's tennis that much until semis or quarter finals, because the depth is just not there. Most of the time it's a top 20 girl just bulldozing her opponent for like 40 minutes.
I saw a bit of the Agassi match, I was out having some drinks. Apparently it's a well known fact on the tour that Andre's conditioning is second to none. He seems to thrive on these long matches because he can readily outlast his opponent. My friend and I watched his match with Pavel (who is an incredible player, amazing backhand), and after he won he looked like he was ready for another set, while Pavel had been sucking air the whole time.