Yours' is somewhat a high case number (the lower is better). DV-2007 interviews will only begin in October 2006 and will continue until end of September 2007. If we assume that the DV-2007 will progress at the same rate as it has been for DV-2006, then your case will be "current" (called for interviews in that month) only in September 2007. That is also the last month for DV-2007 processing. You will receive the 2nd letter 4 to 6 weeks before your interview date (sometime August/July 2007). [However, there is no guarantee that someone will receive 2nd package (= interview) even after filling out forms and sending to KCC in time.]
You can monitor the progress of DV cases in monthly Visa Bulletin (published before 15th of each month) at the official website:
http://travel.state.gov/visa/frvi/bulletin/bulletin_1360.html
Once you notice your number for DV-2007 is within the "current" number for AS region, you may choose to call KCC (say, around mid July 2007) to know your date in advance, even before you receive the 2nd letter.
Wish you good luck.
-Mon