A23 has it about right. I ahve a friend of mine that got into Columbia this past year with a BTL, but this is definitely the exception, and it is becoming more and more uncommon.
Word on the street is that Fordham did not accept any BTLs for the Class of 2013. As a rule (though there are definitely major exceptions) BTLs have serious difficulties in the research, writing, and public speaking aspects of the law school curriculum. Be prepared.