[hammerdr]

See: Accenture.

It's a consulting company not a product company; it may be significantly different when "making partner" at a product company. However, from what I've heard, each partner at Accenture essentially runs his or her own business within the larger scale of the organization. Success is directly tied to the success of the internal mini-businesses. It is, however, an example of a company where IT professionals can become equity stakeholders in a private firm.

I imagine a product company would need to make the partners in charge of one product each (or maybe a couple of partners on one product) in order to avoid the "Too many cooks in the kitchen" problem.

[mathattack]

Though your premise is correct, Accenture is public, not private. They (like many others) wanted to expand beyond pure consulting, and the partners wanted to cash out.

Accounting and law firms may be a better example, though even they aren't as entrepreneurial as you think. They have their own regulations and internal politics.