My thougts on the casting choices:
serena-she's ok, could be a little prettier, taller, special etc.
blair-also ok, something is a little off about her though.
nate-pretty good! i dont like the hair though
dan-also pretty good but maybe a little TOO cute, however, his voice is PERFECT. i dunno i think it just fits exactly how ive heard it in my head while reading haha
jenny-SO BAD! wheres the curly hair and the huge boobs!? what the hell were they thinking? she's practically prettier than serena in the show which is obviously NOT what her character is supposed to look like.
Also apparently, they actually CUT OUT Vanessa's character from the show. i dont understand why but its pretty stupid.