iPhone SDK and the Single Application Policy

Apple announced last week that you will be able to run only one application at a time on the iPhone. This means you won't be able to have applications that run in the background, maybe keep a connection open to a server and notify you when appropriate.

I see really two classes of applications that will be in great demand:

1. Games. Obviously.
2. Push applications.

By push applications, I mean applications that always have the latest information for you ready to use. (That information can be pushed through a connection which is left open, or the application can poll the server from time to time to download the latest information is almost an implementation detail as far as this discussion is concerned.)

Consider these examples:

• An IM client;
• A Twitter client that notifies you when one of your friends have posted a new message;
• A Podcast application that downloads shows over the air (say at 3 in the morning, so it doesn't bother anyone);
• A New York Times reader, which always have pre-downloaded for you all the latest articles from the New York Times;
• A Skype client, which notifies you when someone is calling you.
  

It looks like Apple's policy will prevent developers from creating this type of applications. Talk about a missed opportunity!