The text of the act, H.R. 1249, is hard going and the USPTO's America Invents Act: Effective Dates document is a useful listing of the key provisions as well as giving the dates the legislation becomes active.
Perhaps most of interest to those in the rest of the world is that the USA will, for patent applications published on or after the 16 March 2013, become a first-to-file country. This means that in case of conflict between patent applications for the same subject matter, it will be the earlier filing rather than invention date that is vital. The filing date could be in another country under the Paris Convention, where the applicant wanted US protection. Now all countries will use first-to-file, although Brad Pedersen and Justin Woo argue in some detail that it's not quite the same regime.
The blog did not mention "the dog ate my homework" provision.
The USPTO link is
The link to Pedersen/Woo