I think my dream - and an OMAP3430 with oodles of on-device storage will enable this - is:

1. Modern, fast language and APIs making doing the right thing easy.
2. Powerful, cross-platform IDE with proper code complete (perfect for quickly exploring new APIs)
3. Compilation on-device: plug it in (via USB: ad-hoc wlan or zeroconf just don't have the proven track record, but they should be supported too I guess), launch the IDE (or use a text editor if you've not got one)
4. Remote debugging: step through code in your IDE whilst it's running on the device.
5. VNC or somesuch UI duplication so that you don't have to switch your focus from one screen to another.

(2) means you no longer need an SDK environment which doesn't match the device; you don't need to faff with Scratchbox or sub-optimal qemu; you can develop on any OS.

It's just cleaner architecturally. Pre-release development would still require an SDK, as would any development before you get a device, but for the majority of developers I think this'd be a real boon.

Unfortunately, I don't think Maemo SoftwareDevices are really planning on offering such an easy to use path for developers: ESBox looks promising, but is complicated to install; still requires Scratchbox etc. etc. And most comments I've seen suggest that Scratchbox "works for them".