Dr who. Theories on river song? I ncluding mine?

I have a feeling she could be the doctor if you watch the second to last episode of series 5 the pandorica opens the daleks say "The cracks in time are the work of the Doctor" to which the doctor replies "No not me the tardis and im not in the tardis am I" but who else is RIVER SONG and then the daleks say "Only the doctor can pilot the tardis" so my theory i hope is right she must have something to do with it possibly may be we will soon find out Series 6 - 23rd April :D