Marine Scholarship number less than 600 too
The Marine Corps Scholarship is very competitive and it would serve people better to learn as much as you can beforehand to judge your competitiveness. And here's something to ground you: Marine candidates who come out of the USNA are few compared to class size - maybe 75-100 graduate each year from the USNA. Going to the USNA DOES NOT mean you can just choose the USMC route; you try-out for it during your first 2 years and are accepted or declined by your junior year.
Marine Option scholarships in 2010 numbered 560: 274 Eastern Region and 286 Western Region. These get sprinkled over 6 recruiting districts and their sub-stations for filling. Likewise there are federally enforced minority regulations that are also a part of the process. This year mandated that of the 560 awards available 99 be for those of different minority groups. My son's NJ unit had 11 scholarships to offer and the poolie group numbered about 24 when all was said and done.
Although the USMC doesn't require ANY specific major, certain majors or career ambitions should be obvious - if your goal is to pursue a medical degree, a nursing degree, a dental degree, become a psychiatrist, physician's assistant, opthomologist, or religious minister, the USMC Scholarship is not for you. The USMC wants to create officers for combat assignments: Infantry, Armor, Air, Artillery, Communications, etc... and the requisite supporting units. The USMC does not have doctors, nurses, religious personnel, etc... All those roles are in the US Navy.
Likewise, even though your GPA is 4.00 and your combined Math and Eng scores on the SAT are 1500, if you can't run 3 miles in less than 23 minutes(men), do 45 crunches in 2 minutes or do any pull-ups/hangs(women), the USMC is not for you. OCS is EXTREMELY physical and for the kids doing OCS the summer of their junior years, it is only 6 weeks long. Anybody who shows up at Quantico that summer with less than a Class 1 PFT, is going to be at severe risk of washing out.
So the bottomline is that Marine NROTC Scholarships are very competitive and each area of assessment is weighed in the process: academic, minority, fitness, and extra-curricular activities.