A few observations:

1) She has a nice voice (we may debate autotune but isn't it far worse when someone actually has a very rare gift and doesn't continue to craft their art?

2) Releasing it after the holiday may be unplanned. It's possible this was not supposed to be released. However, if it was planned there is a bit of genius in the move. What other Christmas song will sit in your memory as having been released after Dec. 25th? Probably only this one.

3) Rap (especially hardcore which doesn't apply to the current popular bubble-(w)rap variety) in general, is not a long-term prospect. That applies to everyone. Much of the lyrical content, relevance, and visual appeal is youth-oriented. There are cycles. If an artist wishes to focus on commercial appeal [though many true artists would rather remain underground then stake their essence to a corporation] evolution is necessary. Please note: Queen Latifah, Lil Kim' and -most recently - Nicki M, Many artists also merge the two genres (longer note "singing" and rhyming) such as Lauryn Hill. A few have tried to go the other direction and add rapped lyrics into longer note songs (Brandy, Mariah). Although, much of this is cultured perception. Recall Whitney Houston's "Whatchulookinat:" If the lyrics of a femcee - and a bit more laced with "spice" - a similar song may have been expected. In her case, it was simply odd [only because we expect content of a certain topical nature].

It isn't just form, there's also a steong expectation of content.