According to the American Bar Association law school enrollment for the JD degree in 2007-08 showed only very slight changes from the previous year. "Total enrollment for J.D. degrees increased from 141,031 to 141,433 from the academic year starting fall 2006 to the year starting fall 2007. The increase in first-year enrollment was smaller, from 48,937 to 48,964 or only .1 percent."
For more statistics on legal education including enrollment breakdowns by gender and ethnicity, tuition info, and stats on degrees awarded, please see the ABA's Legal Education Statistics.