How much will Natal cost?

[Mummelmann]

Probably way too much. Guitar Hero costs around 140$ here and Wii Fit around 180$ so Natal will probably nudge the 200$ mark and effectively eliminate at least one potential purchase on that ground alone (mine).
This is expensive technology, it would be better suited to launch with the next x-box imo, and by then the prices would have come way down.