We've already seen flopping from Ivanovic and Radwanska. Kvitova struggles again to a 3-set win. I have no faith in the rest of the top 20 to do anything to challenge Serena. It's continually going to be in the hands of Maria and Vika to play her in semis and finals. But with their combined 4-24 record against her, I wouldn't exactly be putting money on either right now.
I always hear the commentators talk about the great depth of the women's tour. Maybe that's true about the second and third tier. The players ranked between 20-40 are probably more talented than in previous generations. But I believe this tour is extremely thin and bereft of true championship talent near the top. The top 10-15 as a whole just aren't getting it done and that's why we see a 31-year-old dominate in ways never seen before.
You would never see Henin, Clijsters, Davenport, Hingis, Capriati, or even a Dementieva all in their primes let this happen. They had losing records against Serena, but they beat her many times and didn't get intimidated. Hingis and Henin beat her 6 times, Capriati beat her 7 times. Even weak-serving Elena beat her 5 times.
So little mental-toughness and self-belief on tour these days. It would be so boring and sad if Serena rampages easily through Rome and Roland Garros and Wimbledon.....etc. Where does it end?