I think NSC is processing cases based on RD. There are fewer EB2 cases with RD in 2003 and 2004 compared to EB3 cases. Hence the apparent EB3 flood.
Once RD goes into 2005, you'll see a mix of EB3 and EB2 - in any case EB2 are much less than EB3s - so the trend would always be more EB3s when dates are current.
btw, there were about 3 or 4 EB2 approvals here in the last few days.