In Act 2, Scene 2 of Romeo and Juliet, what does Romeo overhear Juliet saying about him and about her feelings for him?

Quite simply, Romeo overhears Juliet proclaiming her very famous "What's in a name?" speech and, in doing so, declaring her love for Romeo.  Ironically, Juliet's speech stems from the age-old feud between the Montagues and Cauplets.  Juliet says, "Deny thy father and refuse thy name! / Or if thou wilt not, be but sworn my love, / And I'll no longer be a Capulet."  This, in a nutshell, is what Juliet is saying here:  refuse your name of Montague, Romeo, or I will refuse my name of Capulet; in this way, we can become lovers.  In regards to Juliet's feelings for Romeo, although she doesn't use the word "love" here, she does say, "Take all myself."  Of course, perhaps she would have uttered the word "love," but Romeo interrupts her before she can do so.