I posted something on Jan 16, 2013 that came out to about 412 million shares. You can easily add the 6 million Deerfield shares and the make an assumption on the ATM shares. I don’t think that the employee shares or options should have increased that significantly since then.
http://agoracom.com/ir/Mannkind/forums/discussion/topics/559191-updated-share-price-model/?message_id=1764954#message_1764954