Make it possible to create arbitrary sized volumes and attach them to linodes on demand.

Maybe with a hotplug type interface.

And generally I'd be more fond of more granularity separating disk assets from cpu and memory assets.

Personally I think that the bundled disk space is more than I need. Others may need more disk and less cpu/memory.

Also:

Maybe allow multiple linodes to attach to the same storage device in a read only fashion.