Apple has introduced a device that connects to your TV and brings content into your living room.
No cable provider, no tuner, no service fees, just digital content on demand. Pure and simple.
Tivo on the other hand is a middle man. Tivo is a broker between the networks and the user. The time shifting functionality gives the illusion of control but the truth is the networks are still driving your viewing habits. Today content is control and the networks have the content... but the control is changing hands...
Consider Apple's relationship with some of the largest TV networks...
The ABC network is owned by Disney. Steve Jobs' company Pixar was acquired by Disney and Steve is now the largest shareholder and on the board of directors for Disney. Now consider that ABC is leading the way in moving content online. It's not a leap of the imagination that Apple TV could provide on-demand content from ABC.
View the show direct with commercials or buy an episode to keep for $1.99. Plausible?
In the same way that people are realizing that they don't need their land-lines for telephones people will begin to realize that they don't need their cable providers for TV content. If ABC leads and makes money at this the other networks will follow.
Get your news online, get your weather online, get your shows online. What's left?
Live sports... Ohh, didn't I mention that ESPN is a subsidiary of Disney.