Seeing as Amazon's being dreadfully reticent about launching the Kindle in the UK, why not beat them to it and launch a store with a decent selection of e-books. While Apple's at it, it should work out deals with magazines and newspapers to bring us dedicated iPhone publication subscriptions. E-book readers apps like Stanza just aren't enough.
Augmented reality apps
We're getting excited by apps overlaying data onto live video on the iPhone 3GS but Apple won't let them in the store yet. TwittAround (a nearest tweets app) and Nearest Tube make brilliant use of the iPhone 3GS's built-in compass, video camera and accelerometer, it makes sense to make them legitimate apps. In the meantime, only folk willing to Jailbreak their iPhones can wonder at them.
A Genius feature for apps
Genius is a great (if flawed) way of finding new songs and artists. With 50,000 applications in the store, it's really time to add a way of filtering out the ones that we'll like. It's all too easy to spend days clicking through curious but ultimately cruddy apps.
A consistent policy for approving apps
The Nine Inch Nails iPhone app was initially refused because it linked to songs with explicit lyrics but iTunes stocks the band's music. One fart machine app was refused while another was approved. The euphemistically named Hot Dog Down A Hallway is fine but an innocuous puzzle of Soviet Leaders falls foul of the censors. Apple needs to apply some clear and consistent rules to app approval, treating them just like other content on iTunes.
An easy way to filter and buy age-restricted content
On a similar note, the South Park app which allows viewers to watch episodes of the fantastically foul-mouthed show was rejected. Yet, Apple sells episodes of the show elsewhere in iTunes. There are settings for selling age-restricted content in iTunes and iPhone OS 3.0 so it can't be that difficult for Apple to make buying naughty apps as easy as rude songs or risque TV shows.
What else do you want to see added to the App Store? Let us know in the comments or hop over to the forums to tells us what your favourite apps are.