It's a long story but basically: Nokia will not officially support MeeGo on n900. Community is doing port and some Nokia employees are lending a hand too. Drivers for n900 are still closed but community are writing open source versions (e.g. battery management) MeeGo for n900 is till very immature. The next release is due in October and will have a gui (maybe very basic version but feature complete?)
Nokia know full well that if other venders join the MeeGo bandwagon, then their job becomes a lot more competitive on that front. Nokia became complacent, they were top dog and didn't/don't put R&D or customer upgrade paths in the places where their customers really want it. This is something that will drastically alter their hand now with MeeGo. They will have to continually be the best to keep on top, Android and Apple aside.
This, among the other reasons I've stated, is why I believe there are so many people feeling abandoned, and refer to the N900 as a dead platform. And in this, I can't disagree with them. I have my own reservations, as I expressed, about the future - even of MeeGo - because of those hardware components and the legal issues you are referring to. As long as Nokia holds the chains on those (whether they want to or not is not my point) - then when Nokia leaves the platform MeeGo will be that much more difficult, or suddenly need to be made illegal, to port any of the newer community builds or future MeeGo versions because the "blobs", as you call them, can no longer be obtained from Nokia.