There are loads of things that I'd
like my iPhone to do, but at the core of these there's a few things that I think any smart phone
should do:
1. Copy & paste
1. Send SMS messages to multiple recipients
2. Send contact details via Bluetooth
3. Work as a Bluetooth modem
4. To do lists (syncing with iCal/Mail)
5. Notes syncing (with Mail)
6. Voice Command & Voice Synthesis
7. File browser (i.e. "Finder")
I really hope Apple sort these basics before getting on to fancy stuff.
As for Disk Mode, this is useless given that the iPhone only has 8GB, and the vast majority of users probably use all of that anyway. Disk Mode would only be interesting in combination with a File Browser (see above).
Just my personal opinion