It’s beyond question that Twitter is an absolutely dominant force in online social networks. along with Facebook, it has emerged as one of the clear winners of the race to capture users and mindshare. With its deep integration into Apple’s iOS 5 software, announced Monday, it has cemented its lead while simultaneously ensuring that it will continue to exist, in one form or another, for the foreseeable future.

Both Apple and Twitter gain quite a lot from its integration into iOS. iPhone users are very happy that Apple has finally delivered a system-level integration with a sharing app widely adopted by most them already. It has partnered with one of the two biggest social networks in the world to give those users access to sharing features throughout the interface including photos, Safari links and more.

So what has Twitter gained from this? A practical guarantee of immortality by aligning itself with Apple.

Now, while it is true that nothing lasts forever, the future of Apple as a company is about as bright as it has ever been in the history of its existence. Despite the slight drop in stock after the announcement that two of its major new products, iMessages and iCloud, would be offered free to users, it is still trading at generally phenomenal levels that many consider to be greatly undervaluing the company.

Now that Twitter integration has made its appearance on the iOS platform, Apple has made a statement that it is in the partnership for the long term. Nothing about this release of iOS is tentative, every major feature is a bold stroke for the company, which has traditionally focused on a relatively slip update portfolio for each new iOS.

There have been many questions about how sustainable Twitter is in the long run and abject failures like the #dickbar have not helped alleviate concerns about monetizing the service. Despite whatever sum is being paid out to Twitter to integrate its services into iOS, if any, the halo effect of being embedded into many of the current 200 million iOS devices in the wild is nothing to take lightly.

The iOS platform is an excellent way for Twitter to propagate itself across boundaries of user demographic. If your Mom or Dad weren’t on twitter before this update, they very well may be afterwards. Historically Apple has removed very few major features from iOS software unless it is for performance reasons. Once Apple has put this kind of effort into integrating Twitter, it is highly unlikely that it would strip it out in the future.

If Twitter falls onto financial hard-times, it has a company with enormous cash reserves and an innate interest in their survival to turn to. Apple has played its hand with Twitter over Facebook and they simply won’t let troubles with the company interfere with their plans.

Apple doesn’t make moves like this lightly and obviously considers Twitter a safe bet. If that bet turns out to be wrong however, Apple will do whatever it takes to ensure that Twitter remains a part of its service. Ensuring that Twitter’s lifespan will be a long one.