I am at the Open Nordic Conference in Skien (about two hours south-west of Oslo), listening to Lars Ingvald Hoff from Telenor R&D talking to a bunch of developers about the new, platform-like SIM cards coming out.
The new SIM card has plenty of memory "gigbytes", USB interface (means you can get data from the SIM card real fast), virtual machines (or at least virtual memory areas, closed off, called SSDs). Tele operator has control of the card, application developers can install SSDs (whatever they are) that run in a sandbox. One business model may be that operators will charge rent for space on the SIM. Seems like a pretty full architecture to me. Translation HMTL to APDU (command language for phone) in a web server on the card, so in principle you could move your cell phone onto the net. Alos has a "Java Card", where you can to some extent can have interoperable applications running between manufacturers. Secure and certified environment, not full Java stack , but a pretty good selection. Standards based, not operator-specific.
FC: New short-range communications protocol, can be used to access payment terminals and similar, secure devices.
Apps can be downloaded and installed via a variety of protocols (among them BIP (Bearer Independent Protocol) directly to the SIM card.
In other words, mobile phones are going to open up to a much larger extent. I predict that the SIM card over time will become you – an identification and payment device.
Future future SIM card – you will get IP stacks, threads, full Java virtual machine, will look more and more like a server.