Bold statement there,I remember Daniela serving very well in 2007:14 aces against Harkleroad at the AO,consistently at 170-180 kph in Indian Wells(a major reason she won the title),serving Ivanovic off the court at Rosmalen and having a great indoor season behind a reliable first serve.
Daniela's return game has always seemed aggressive to me. What is different is that her anticipation is so much better at the moment,allowing her to hit clean return winners,which is always pleaing to see.You are right there were moments of good serving in 2007 like at Indian Wells or Rome. But for majority of the season Daniela was either playing the %, taking off some pace of her serve in order to get it in more often (which didn't work quite well if it was the case, because placement wasn't much better nor did she get enough cheap points), or was simply unable to generate the same speed for a longer part of the season. From what I read Ivanovic's biggest problems were Daniela's low bouncing flat shots, I didn't saw the match myself to confirm that though. As for the indoor season, that's where her serve regressed the most I would say, but she made up for it with precise footwork (for her standards), consistent groundgame and fighting attitude. 2nd serve was ultimate crap during the whole year.
well personally, I find it boring to watch those three players and a bunch of other players as well. And you could say that all Daniela has to do it move Cornet/Wozniacki etc from side to side and shoot with pace and she will eventually hit a winner. There is nothing dangerous coming from the other end. It is two different styles of tennis.I thought you were a fan of Wozniacki.
I personally can always admire her curves in case her game is starting to bore me. 
For the record, I think Kirilenko plays quite aggressively and tries to win points by herself, but lacks firepower against the big guns, so it sometimes seems like she resorts to grinding and pushing. She possesses nice volleys too.