Indeed a $99 xbox 360 with kinect is coming but there is also a mandatory $15 a month subscription with it for a set period, as far as I read. You get gold membership with that subscription though. This is atleast what I've read on websites, no idea how long you have to pay $15 a month for though.
Someone correct me if I'm wrong though please
I have an old 360 I was planning to give to someone as a present (as they are financially in a difficult period and it would cheer them up I think) and get a new gen 360 and this $99 offer seems very interesting for me