$700 + a broadband connection!
Yes, broadband penetration is pretty solid now ... but still, there will investment beyond just buying the unit in terms of either buying a wireless router or setting up another connection in the room with the unit.
TiVo will reportedly only support FTA content ... not Pay TV.
The question you have to ask is, when was the last time you really (and I mean $700 really) wanted to watch two shows at the same time on FTA? I know I generally don't lose sleep when choosing between watching the Big Brother Daily Show or Two and a Half Men reruns.
TiVo works well in the US because there is a heap of content available. I am not sure with 5 FTA stations (lets not pretend any of the HD stations really offer anything compelling as yet) such a device is needed.
I'm thinking Seven had to launch this before the Olympics as this will be the only time in the next 4 years when time shifting TV will be something people actually feel they need ... for the two weeks the Olympics are on that is.