Maemo sadly has it's share of closed parts - but we're mostly stuck with them due to the lack of really open alternatives that would interface well (yes, I know, it's mission impossible without proper docs and all). OTOH with the upcoming releases, even in a worst case scenario, it has already been told that there will be a no-DRM mode in which you can flash whatever your want (stock MeeGo comes to mind as the most likely alternative) and hack it till your nose bleeds, so what kind of lockdown are you talking about ? It's not like there is bootloader lock or rooting required. And yes, I know my nose is going to get rubbed in BME et al, but at least it's part of the HW adaptation so you can get MeeGo images with it.