Sorry taralej, didn't mean to ignore your post, I just got carried away. You should add some points in the discussions from the last pages to the main post, because a lot of people contributed a lot of interesting content that could save ppl from asking a lot questions.
Getting back on topic let's look at it objectively, 1st of all we don't have stat weights like those people on retail do but,
if i had to guess, mastery is close to agility at high end full available gear lvls(
http://elitistjerks.com/f78/t111329-..._12_01_2011_a/) but we can speculate mastery is somewhere between 1.5 and 2(since we don't have a function on how mastery works and the closest thing we can use are probabilities at which i am not good, we can only assume). That given however SS is still our top dmg contributor, even at my current 22 mastery, followed by melee attacks. This could be the result of too much haste doing what you describe. You could test this with low gear however, you don't need high end gear to do it(your best pick you probably be crafted or epic pvp gear since it only has one type of stat on).
Now since SS is still our main contributor, haste remains strong, even if we lose mastery procs as you predict we should be getting new ones anyway, in total averaging out the number of procs/sec to something consistent to our mastery proc %. And also energy means we can use our support abilities more freely, Feint, Recuperate should be used as needed to stay alive, otherwise you're just playing a warrior w/o the plate. I am not even go on about how haste is a very important asset in aoe dpsing.
Then there is also the way chain procs work, as far as i've noticed they proc instantly off each other, and did not seem to go on past the millisecond mark, however there are so many things that proc mastery that it is very hard to tell if something like you predict happens or not, truly. As i said it needs to be tested.
You should post this bug report, tbh this thread is evidence the bug exists and it's been discussed vigorously, not to mention every rogue on molten pretty much rolls combat and stacks mastery.
Do you have the numbers at which 4.3 gear would bring our mastery to? What about haste? Depending on that we could try to deduce what could happen. There is also the reverse of the medal, we could see a fix in 4.3 since I bet molten would be picking up a more complete 4.3 engine that could have already fixed the bug.