iOS 5 not iPhone 5 is Apple's big deal today

Apple's "Let's Talk iPhone" event is just hours away, and there's still plenty of argument over what will steal the show. New iPhone hardware will obviously have a significant impact on Apple's bottom line for the next twelve months. Whether the company launches one new handset or two, though, and whether the new flagship is an evolutionary iPhone 4S or a revolutionary iPhone 5, sales are likely to remain strong – after all, even more than a year on, the iPhone 4 is still in high demand. While that's all a big deal to Apple (and carriers), it's software which will make the broadest difference.iOS 5 may struggle, as software, in a world where eye-catching hardware pulls on our lust-strings just as much as our purse-strings, but considering the legion of users that already own Apple devices, the new platform's release is a far bigger deal than a few new handsets. The iPhone 4 – along with the iPad and iPad 2 – will get a new lease of life, in one fell swoop polishing away some of the flaws (like notifications) that have grown into a common critique point from Android and Windows Phone rivals. There's also the possibility that the company could use iOS 5's release to bring App Store access to its favorite "hobby", the Apple TV. It's unclear whether Apple will be charging for the iOS 5 upgrade, but even if it does that's going to be far cheaper than picking up a shiny new device. [Thanks to all who flagged up that iOS 5 will be a free upgrade!]

Apple looks set to play this to its advantage, however. iOS 5 may have shown much of its hand back in June, but the company is expected to have a few tricks up its sleeve nonetheless. Chief among those is Assistant, tipped to be a complex voice-control system that will allow iPhone users to control their smartphone via natural speech commands. It's likely to be a highpoint of Tim Cook's presentation today, but it's also likely to be limited to the very newest hardware.

That, so the tipsters say, is because Assistant – although relying in part on Apple's cloud servers for the speech processing aspect – has above-average demands for processor and memory. A dual-core chip, like the Apple A5 as already found in the iPad 2, and more RAM than the current iPhone 4's 512MB are apparently baseline requirements. In short, if users want the Assistant experience, then upgrading their existing iPhone simply won't be enough.

Remember, SlashGear will be liveblogging the whole Apple event at 10am PT (that's 1pm Eastern) at so join us for all the news as it's announced. To get up to speed ahead of time, check out our pre-event rumor roundup.