With rumours of a pre-Christmas firmware update to 1.1.3, here's my wish list. I'd probably forgo the Jailbreak for these – currently I only really use the MobileScrobbler app from the iPhone dev scene but i'm finding that it keeps logging me out and doesn't cache track plays. Everything else seems to pretty much be fluff (i.e Pirate-photo-app, eBooks and Games) or unstable (Summerboard kept rebooting for me and broke access to photos).
I'm going to get my dev head on and see if I can come up with something useful, just as soon as I find the time – i'm currently pretty busy with work and university studies.
Calendar – Respect iCal colouring for different calendar items.
SMS – Ability to cancel a message in transmission.
SMS – Send message to many recipients.
SMS – Forward sent or received message to new recipient(s).
Copy & Paste between apps.
Use a track from the iPod as an alarm sound.
Direct download of mp3 from Safari to iPod. Podcasts for example.
Save images from Safari to Photos.