My understanding is that each of the four sections of Comlex I is 200 questions (w/ 4 hrs. alotted for each section). So 800 questions over the two rapidly approaching days.
Just to warn you that some booklets may only have 198 questions or they may add a few extra questions and go to 204. Don't panic. You didn't miss any questions. NBOME is only sampling different questions for a trial run.
Usually, the first and fourth booklet may be easier and, therefore, you may go faster. That is especially nice at the end of the 2nd day.