Cool blog post! From your resume it looks like you worked at Blackberry earlier this year. Do you have any thoughts about the differences (cultural, technological, etc) between working for a large company and working for a non-profit organization?
Related: one thing I've noticed some people don't place enough emphasis on when choosing initial internships/jobs out of school is the business models of companies, and the direct effect that can have on the working environment.
In this case, while Mozilla is technically a non-profit, rather than being funded by donations it makes the overwhelming majority of its money by sharing in the advertising revenue generated by the search engines which come pre-installed in Firefox (see http://www.mozilla.org/en-US/foundation/annualreport/2010/fa...). Therefore, even if Mozilla does absolutely nothing in terms of improving any of their products, they will still continue to make money (in the short term, at least), which lifts quite a bit of stress off everyone who works there, and let's management take a longer view perspective in general.
Professional service firms (i.e. tech. consulting and agencies) are effectively arbitrage plays - they sell the time of their employees for $X / hr, but only pay the employee $Y / hr, and then collect on the spread. If these companies ever stop selling for just a few moments, the arbitrage breaks down (as they still presumably need to pay their employees...). Therefore, there will likely to be more "stress in the air" in these types of firms, as in some cases all it takes is 1-2 contracts to be canceled for the firm to be unable to make payroll.
Hit driven businesses (Which Blackberry as a whole arguably is not, due to the significant revenue driven by their enterprise server), have a different set of issues, which is that losing really sucks for morale - therefore if the company you work for is focused on building a better mousetrap, and slowly over time people internally begin to doubt the quality of the mousetrap they are working on, that can make it really frustrating to work there, regardless of the other perks the company may provide.