Don't know if Chrome is going to overtake IE, but it would definitely be good to see it give it a go.
Additionally, most employees work for Mozilla Corporation, which is a for-profit corporation owned by the non-for-profit.
Once they've paid off some of the technical debt they built up with long-term supported releases, and they have a product that will wow Chrome users, I'm sure you'll hear their marketing department kicking into gear.
Also, exits are only a consideration for startup employees. 98% of programmers are working for corporations that have already had their exit, and so the primary considerations (as they are for employees everywhere) are salary, benefits, and options. I can't see Mozilla being too far behind the market on salary and benefits, and stock options tend to be pretty worthless for the average employees anyway due to blackouts and whatnot.
Not only that, but also a choice on our privacy.
If either MS, Google, or any such company gets a large percentage of the user base (75%?) again, the web is going to be locked and not very privacy oriented again. Don't think for a second that Google cares much. They don't do evil, but they'll do as bad as their business requires.
They do use their quasi monopoly right now to promote Chrome and it works extremely well. Chrome is a very good browser but you may understand that such growth is not due to that alone, in fact, being a good browser is only a requirement, not the actual factor of the growth.
Unfortunately it will be used to enforce Google control over the web.