Spring Awakening and Rent are definitely cut from the same mold. However, there are a few differences. I'd say Spring Awakening has a teeny bit more depth in its music. There's a lot of very nice string orchestrations you won't see in Rent. While SA has pop/rock music, it's not really presented in Rent's fashion of "this is a loud rock musical with lots of drums and electric guitar..." Also, Spring Awakening is about teenagers still in school while all the characters in RENT are in their twenties- trust me, it's a huge difference.
I love Rent, but I really doubt it would have been as popular if it wasn't for the Jonathan Larson story. Whereas... Spring Awakening doesn't have a fantastic news story to keep it going.
However, once SA gets out there, it's going to hit strong. I think a lot of teenagers can relate to Spring Awakening more than they can relate to RENT, and you know how many teenagers love/"can totally relate" to RENT. Because SA focuses on the troubles of school, I can see songs like "All That's Known" becoming really popular among high-schoolers.
Cosette: Roses are red.
Marius: Violets are blue.
Eponine: You're so in love!
Marius: And so not with you.