If the iPad is succesful, then it will affect me whether I buy it or not. Just like Micrsoft's success has filled my inbox with spam from botnets and limited my tech choices in a myriad of ways. Just like Facebook's success means there's no room for an alternative until they really shaft people.

It's called network effects and it's one of the basic elements of information technology. That's why we care about what the idiots are buying and what the power-crazed shysters are selling them.

Ironically, the answer to your question is that many of the other large companies (e.g. Microsoft, Telcos) have already locked people in and don't even need to care about competing at Apple's level in order to rake in the cash, they just have to occasionally intervene to prevent competition from entering their market. Does that sound familiar in the context on Apple?