There has been an incredible amount of anticipation for the iPhone 5, and it’s expected to be unveiled at an Apple event on October 4.

Something else that has been widely anticipated by Apple fans is the launch of a Facebook iPad app, and according to a report from Mashable, this too will launch at that event along with a new Facebook iPhone app.

There’s been a fair amount of drama in the news this week about the launch of the iPad app (or lack thereof). The engineer who created it put up a blog post that’s been making the rounds, saying that he left Facebook for Google, partially because the company wouldn’t released the app, which has been completed since May.

Perhaps Facebook wanted to get its huge new announcements out there first (Timeline, new Open Graph, etc.). Facebook is changing a lot now, you know.

Apple, on the other hand, announced that iOS 5 would be fully integrated with Facebook rival Twitter.

According to Mashable, whose sources are cited as “two sources familiar with the situation,” Facebook may also be announcing its rumored HTML5 mobile platform.

As far as the iPhone 5 itself, this infographic from PaidViewpoint looks at who’s most likely to upgrade to the device and the features they want: