nomis5 - 9:46 pm on Jul 1, 2011 (gmt 0)

1500 pages of unique content

?

Put yourself in Google's position. Can anyone generate that number of pages of unique, quality content in one go?

No, be honest, no one can, except in the most unusual circumstances.

So, go back to the drawing board and plan out a phased release. Of course, if it's not unique, quality content then expect the inevitable Google reaction.