The primary difference between intrapreneurs and entrepreneurs I have seen so far is that they are trading freedom and reward for a relative sense of safety.

In general, I find there are a few key motivations to starting businesses or similar ventures:

• Fortune — Making money, either as a goal in itself or to acquire physical wealth, stuff, status symbols
• F#@k — Having power (including the power to fulfill erotic desires)
• Fame — Being attractive and recognized, held in esteem
• Fate — Often triggered by personal relationships these businesses are focused on alleviating suffering
• Fulfillment — Personal creative expression, first as a means of self-actualization, eventually transcendence and ultimately as self-realization as creator.

These roughly correspond to our basic needs as humans (mostly based on Maslow, but also Rosenberg).

The impulse to act and to sustain action is usually driven by an underlying need, from physiological well-being, to safety to higher human needs like self-actualization and transcendence.

Both intrapreneurs and entrepreneurs are usually triggered by a combination of these needs.

While entrepreneurs have a completely open playing field in regard to their creation, intrapreneurs trade that freedom for the relative safety of their paycheck. Consequently, they are also foregoing the possible financial reward (or fortune) of a new venture (mostly due to current corporate policies that don’t do employee/equity models well). This payoff can be earned by entrepreneurs who are taking the financial risk of failure to start a new venture if it turns into a success.

In the end, it doesn’t really matter how you create the future, as long as you create it ;-)