Jelena is an all power baseliner. Yes she hits the odd dropshot, but her strategy every match is to whack the ball very hard.
And she used to succeed. But now there are many girls who either hit the ball as hard as Jelena and as consistently OR mix it up to the extent where she loses her rythmn and consistency.
Jelena's strokes are also very flat, there is no variety in them, and they can look fragile.
I think Jelena is an 8-12 player at best, until she improves her game, serve and movement. Yes she can move, but she isn't in the same league as Clijsters, Henin or Dementieva (her peers).