An email sent out by Apple late last month to select tech reports inviting them to attend an event at their Cupertino headquarters on October 4, which also contained the words “let’s talk iPhone,” tells us that we’re very close to the debut of the latest version of the handset.  It fits in with the four month delay beyond the regular 12 months release cycle.

This is a good time to recap on what Apple has been doing, as well as the expectations and leaked bits of information we’ve gotten so far.

Mobile ad network InMobi polled iPhone users, and found that 41 percent in North America plan to purchase an iPhone 5, and that over 50 percent of these individuals plan to do so within six months of the official launch. This is backed up by other figures as well: according to this infographic, the iPhone 4 accounts for over 48 percent of all the handsets sold by Apple to date, followed by the iPhone 3G with a 28 percent slice of the pie.

Apple sold a lot of iPhones so far, and that number is expected to increase greatly now that AT&T is not the only carrier that supports the device in the US.  As of February, Verizon became the second retailer, but the iPhone 5 will be available via many other carriers according to some rumors.  Mashable reports that Sprint may carry it along with China Mobile, which is not so far-fetched, considering the huge market Apple could tap thanks to such a partnership.

More carriers is a part of the reason Ticonderoga Securities analyst Brian White expects the iPhone 5 to “shatter” single day sales records.  Specs are also a factor.  Longer battery life, more affordable data plans, extra processing power and better graphics are some of the primary advantages customers are looking forward to.