Unless its a legally bound contract I don't think you could hold them to it..
The thing with Microsoft is, its an umbrella for a bunch of teams.. some teams are great.. I mean, god, Microsoft can make some seriously amazing software.. other teams are not so, sadly, they still come under the name of 'Microsoft'..
I'm sure its a ton easier to say this than it is to execute, but Microsoft really need to manage their appearance better by ensuring their teams are being the best they can..
Any direct contact I've heard from IE developers regarding why its so hard to get it right, I'm told the same thing over and over - 'hardly anything is precisely specified on the web'.. but thats it.. theres the excuse, this is why its not working.. but theres
never anything to prove their looking to make it better..
Frequent updates to IE, starting a rich community between standards and other developers both developing their own internet explorer alternatives (such as firefox) or developing for the web..
Odd as it is, Microsoft are in an important lead position with the web.. and they need to be the people that get the ball rolling, for a greater thing than money making and competition.. which is so ensure the web progresses faster and helps humanity itself
evolve (think of how big a thing the web and email is to modern society)..
This can't be something to be done alone, but Microsoft sure are the people with enough position and power to start a union..