The RNC had previously announced the week beginning Aug. 27th, 2012 as their convention week:
linkThe DNC has now penciled in the week beginning Sept. 3rd, 2012 as their convention week:
linkNeither party has decided on a host city for their convention yet. Until such time as the venue is settled, it's possible that things will be rescheduled. I believe Sept 3rd puts the Dem. convention later than any previous major party convention, at least in modern times. When the GOP decided to go with Aug. 30 - Sept. 2 in 2004, they were actually running up against state ballot access deadlines to do so. Will the Dems be doing so this time?
Also, assuming that the NFL uses the same scheduling format into the 2012 season, the NFL's opening night kickoff game would be on Sept. 6th, the same night as Obama's acceptance speech (same issue w/ McCain in 2008). I would presume that the NFL will be able to reach an accommodation with the DNC (as they did with the RNC in 2008) where the game is scheduled a bit earlier, so that it doesn't conflict with the speech.