Some important dates coming up:
August 27-30: Tampa Convention
September 12, 2012: Permanent Injunction against NDAA
October 3: First Debate
October 16: Second Debate
October 22: Third Debate
October 23: First Free & Equal debate
November 5: Second Free & Equal debate
November 6: Presidential Election
Obama won't enter the Free & Equal debates. If he does it not only provides an opening for Paul but for Barr and Anderson as well--the latter two will definitely attack his environmental policies and everyone will attack his foreign policy.
I've included the NDAA as a key date because OTL Obama asked for an emergency stay and was granted that. However, seeing a candidate that has drawn in much of the anti-NDAA crowd among the independents he would most likely lose the lawsuit on purpose, probably admit his mistake in a press coverage, in order to avoid Paul from bringing that issue in the debates.
Also, what about the Auora shootings? You possibly neglected a major tragedy that can dominate in the debates in the topic of gun control.
Speakers at the convention could be: Justin Amash, Rand Paul, Mitt Romney, Justin Raimondo John Huntsman, Gary Johnson, and Carol Paul(since Romney also got his wife to speak why can't Paul).
And with Ron Paul joining the third party debate, I can possibly see "the duopoly" forever broken by this.