the features you've listed are all software features - so they could be added using a firmware upgrade or by a community camera app.
There is a common problem here - non-tech folks compare on what they are used to compare in the past - a smartphone either has or it hasn't got the functionality of another. Maemo devices (and the N900 is no exception) do not fit this mould. Think what would you say if this was a netbook ? 'the built in webcam application has no timer and no settable contrast, etc'. Most people would say, big deal, I'm doing to install a different webcam application that works the way I want it to. And that's exactly the freedom Maemo gives you. It (almost) doesn't matter what the camera application (cannot) do as long as it has it's source or API available and the hardware is actually capable of the required operations.