Adele will be like alanis
one direction like jonas brother
miley like hilary duff
gaga like nelly furtado
katy like avril
rihana like Ciara
nicki like lil kim
Taylor is here for good, I think she will have most longevity out of those listed because, IMO, she has reached a point where she can transcend genres entirely and get away with it. I see her rock album in 2017.
I think Gaga will fade slightly (purposefully), near the end of '14. I see her next album coming out in 2015, I think she'll stop catering to select audiences and slay us with fresh sounds. If she doesn't and keeps up the 'ART' 'LGBT' stanning, I can see the GP letting her fade into oblivion.
Adele might actually fade completely.
idk about Bieber, I think he will fade and comeback, when he's more mature.
bieber? over
taylor swift? not sure about 5 years but she'll fade in the end
one direction? won't make it until 2020
gaga? already faded
katy? yes she'll fade in 5 years
kesha? over
miley? over
Rihanna? never
Adele? will last for 8 years minimum
nicki minaj? already faded. if not, she'll fade in 5 years