Seems that the -D option is not working after revision 7ee93b206a6389e6eb7b9440dc2fae801c77bc9b (Bitbake rev: 45aad2f9647df14bcfa5e755b57e1ddab377939a). The option (or indeed multiple additions, e.g. -DDD) has no effect on the console output; adding -v as the commit message suggests has no apparent effect either.
Fix posted to bitbake-devel mailing list: http://lists.linuxtogo.org/pipermail/bitbake-devel/2011-September/001414.html
Found an issue with that patch, v2 is here: http://lists.linuxtogo.org/pipermail/bitbake-devel/2011-September/001417.html
Fix is now in the master branch in commit dea2fd181aa787c1228c10664856773d5dc4bbe5 and the edison branch in commit 7eb193fc4994b880ce115fc00fb52b4d9cda530e