While the tiger is adorable, and kinect may even work well, I don't see this actually being very popular.
The player base that has built the 360 into what it is, and what MS targeted it for, as well as the PS3, never wanted this.
If they did, again, they would have bought a Wii.
If MS or Sony wanted to target the Wii's demographic they should have done it ages ago, and less expensive, like Nintendo already did.
My fear is that otherwise good games will be ruined by trying to foist this thing into our hands (or... not so much hands... but, well you understand) and shoehorn it into situations where it doesn't belong.
This thing, like all other late-term addons ever, will either be forgotten, or used for some exclusive titles like the:
Eye toy.
Power glove.
U-force.
Dance Dance Revolution Pads.
and Lightguns.
To be done correctly, with any chance of adoption, it should have been done as part of the system identity in the first place.
By the time either device gets "good" and really relevant killer apps, it will be really too late for this generation of consoles at least.
Finally, WTF comprises a "hardcore" gamer anyway? If it's determined by the guy who's willing to spend the most, than the fellow who (with vitriol, granted) suggested that PC gamers are the "hardcore" ones, he's probably correct by that definition.
I would expect it's the buyers are the potential gamer who is uninterested in the current crop of games, for whatever reason, but is intrigued by playing with a clever new controller. The vast majority (hardcore or not) of gamers who already have the 360/PS3 were/are clearly already content.
Honestly, how many people are left, that didn't already buy a much cheaper Wii, with way more titles are planning to buy a MS/Sony experiment that the companies can just abandon if they don't like, it's happened a hundred times before. Nintendo can't give up on the Wii, it's a safer purchase.