Samsung - August 29th event for Galaxy Note 2
Motorola - September 5th event likely for Droid RAZR HD
Nokia/Microsoft - September 5th event possibly for Nokia WP8 smartphones/tablet
Amazon - September 6th event for new Kindles, likely a Kindle Fire or smartphone
Many are expecting the new iPhone to be available on September 21st, 9 days after the announcement. The Daring Fireball opinion is "Why would Apple want a new iPhone and iPad to be announced at the same time" and it makes sense. Apple could let the buzz and reviews of the new iPhone die-down in October and announce the new iPad Mini and get the buzz going again before Christmas.
Event 1: September 12th: Announce new iPhone and iOS 6 (Available Sept 21st)
Event 2: October 16th: Announced new iPad Mini and possibly iPad or Apple TV refresh (Available October 26th)
Seems like a good idea to me, gives people a chance for their pocketbooks to catch up between announcements. Go get your popcorn..it will be good. Hopefully an iOS 6 jailbreak before Christmas!!