Cracked it this morning/afternoon to see if I could. Apparently, I can.
And yes I have a legit copy too. No proof, of course.
Hardcoded to 1.3.2 to avoid having to contact any servers besides the Minecraft Update Tumblr page.
Instructions:
Run minecraft.jar.
Enter username, Login.
Launcher will download Minecraft if necessary, but only up to 1.3.2 (see above).
Play.