I know that feeling, but at the same time, if Marketing makes the sales, and the customers are happy, the plan is working. And I have definitely seen cases where constraints bred creativity, and the ridiculous promises of marketing actually did force the devs to be more creative and sometimes spark some miracle, aka, some really creative and innovative approach to the problem. It also often falls flat, but that's the gamble I guess.
That is management's job, not Marketing. For one, there is no trust relationship that can support that sort of act, but what's the point of project management if the marketing people get to decide the roadmap not only by themselves but individually?
