The new developer beta of iOS 5 released last weekend contained a number of new image filters that should let developers manipulate photos much more quickly and easily. That means if you're an iPhone owner, you can expect to see a wealth of new, cheap, photo editing tools for iPhone and iPad. The new effects are part of the iOS 5's Core Image framework, which is designed to make image processing easier on the platform.
The new programming tools will certainly be of use to developers. Even without these new effects and frameworks provided by iOS 5, the iPhone already is the most popular camera on Flickr. This popularity is, at least in part, due to the great photo editing apps that are already available for the iPhone. For instance, popular photo filter app Instragram hit 150 million photos recently in under a year.
However, thus far most of these apps had to create ad hoc solutions with the Core Graphics framework to manipulate photos since iOS didn't have the tools to handle image processing on its own. While that has produced some spectacular effects, creating custom photo filters is also a relatively difficult and complicated task for developers that has discouraged new apps.
A more likely possibility is that other app developers will start to integrate photo manipulation into existing social apps like Flickr or Fourquare so you won't need to switch apps or fiddle with your phone the next time you want to upload a photo to Facebook or another social service.
iOS 5 is expected to be released sometime this fall and, thanks to the developer beta that's currently in progress, we can expect a deluge of photo filter apps to follow soon after. For now maybe look into some great desktop photo filter apps.