Lots of these are nice points but how did I miss the emulation tools in Chrome, this article was worth the entire read and more just for that, stunningly useful! (I already use the similar thing in Firefox).
EDIT: Having played with it this is fantastic, been able to lock an emulation to the developer tools makes flipping back and forth vastly easier.
Ya! ;)
Point taken on reminding devs to break out of the popular WebKit + OSX environment to do IE, but seriously, no one is using Windows Mobile. I can't find any record of it coming in above 1% of any major browser stat reports. Total waste of time.