If you look at the Oct 2010 inventory there were hardly 3300 EB3I 485 applications for EB3I upto Jun 2002. Between porting and denials 500 can easily be covered and so 2800 is teh usual quota which should bring dates to jun 2002.
Just like you I am skeptical too. I just don;t believe India has so little FB demand that India starts consuming EB visas in EB3.
p.s. - I do think its terribly unfair that the unused FB visas for a country don't come from FB but rather EB. That just goes to show once again the lattitude/discretion DoS/USCIS exercise time and again. This is also a good area to do advocacy.