This morning, Apple sent out press invites to an event scheduled for 10am Pacific time October 4th (next tuesday) on Apple’s campus in Cupertino.

As Steve Jobs is no longer the CEO of Apple, Tim Cook will lead the presentation while other Apple executives may take smaller roles on stage periodically.

For the past few years, Apple has used their annual WWDC event during the summer to announce a new iPhone model and to release the next version of iOS. Neither of those things happened this past WWDC, but iOS 5 is currently at the very end of beta testing so a release next tuesday would line up perfectly.

Apple is also rumored to be planning to release a new iPhone 5 model, containing the same A5 processor and improved graphics capabilities that debuted in the iPad 2 earlier this year, as well as a lower cost iPhone ’4s’ model.

Apple continues to sell the 2009 iPhone 3GS model, despite being introduced over 2 years ago. Apple specifically markets the 3GS as a low cost alternative to a new iPhone 4, so it’s likely that even if the rumor of a special ‘low cost’ iPhone model doesn’t pan out, Apple will reduce the price of the existing iPhone 4 model and continue to sell it alongside the newer iPhone 5.

What would be included, or rather left out, in a budget ’4s’ model? NAND memory, sometimes called Flash memory, would be one prime target. Given the concurrent launch of Apple’s new iCloud service alongside iOS 5, Apple could very well build an iPhone with 4-8GB of NAND, similar to the Apple TV 2 which has 8GB, and encourage App developers and users to rely more heavily on iCloud to store user and application data.

The iPhone 5 is rumored to include a slightly larger screen, potentially as large as 4″, while reducing the bezel around the screen to a narrow strip or potentially even eliminating it altogether. This would leave the total size of the phone the same or only slightly increased.

We’ve also heard that Apple may update one or more of the Mac models either next week or later on in the month. Both the Mac Pro and the Macbook Pro are due for a bump in specs so if you’re planning to buy one of those models, wait and see what happens this month.

Stay tuned!