For better or worse, AT&T was and still is the "premier partner" for Microsoft and Windows Phone. As a result, they seem to be interested in how the experience is going for those of us who fork over money to them. We've been seeing reports of this survey going around starting tonight (even Jeff Wilcox got one) and we just finished ours up a few minutes ago.
The survey took about 15 minutes and was surprisingly detailed and lengthy. Based off of the phone you bought, it asked for feedback on why you bought that phone, your favorite features, order of importance on design, complaints, etc. It also inquired about your knowledge of other Windows Phones e.g. for my Titan survey it asked if I knew about the Focus S and Focus Flash and asked why I did not get that phone instead (hah! If they only knew).
Overall the survey should give AT&T some useful feedback on these devices and hopefully steer them towards more important features in the future. There is a chance to win a $100 electronic "gift card" which is not exactly enticing, but what the heck.