Even if based on Maemo, it is only a ripoff if they don't make their software available for download. Otherwise this is just a "fork", which is ok. It would be more usual not to fork at all, and contribute changes back to Maemo, but this isn't required.

Even if it isn't mostly Maemo, it seem likely that Maemo can be made to run on this hardware which would provide an interesting addition to the Maemo family of devices.