The poll is poorly designed; some people will have multiple "yes" answers to the questions but in the poll you can only pick one response.
As for me...
1) I am a brand new WP user; I just received my HTC Trophy that ordered on-line this past Thursday (12/8/11). It is my first Windows Phone device.
2) I've never had an iPhone, though I will be getting an iPod Touch for Christmas so I can play around with a iOS device at my leisure. I have had an Android OS device (Motorola Droid 2) for almost exactly a year (since 12/10/10). I really like the Droid 2 and will continue to use it, but I do have some issues with Android OS and how clunky it can run after you've had an Android smartphone for an extended period of time. I use the Advanced Task Killer frequently, and try to reboot the phone every 3 charges (roughly 5 days) or so, but I still get more than acceptable lag at times (and I've seen other people's Droid 2's lag even more than mine).
3) Though this isn't a question in the poll, I'll note that I bought the Trophy (and will get the iPod Touch) in large part because I want to see which mobile OS will best meet my needs/wants going forward. As I noted above, Android IMO is clunky, and I don't like the iSheep mentality of iPhone acolytes or the lack of a physical keyboard on any iOS smartphone. (I realize that the Trophy also doesn't have a physical keyboard, but because I also have the Droid 2, that's not so much of a problem.) Right now, my thinking is when I become eligible for an upgrade on the Droid 2 late next year, I will buy a device that 1) has the best-functioning OS that has the key apps/free apps I want, 2) has a physical keyboard, and 3) is 4G LTE capable. I think right now that could be WP, assuming I continue to really like the WP OS after I use it more, but it could be Android if that OS is improved (ICS and its successors should help in that regard) and/or WP doesn't get some of those key apps I want, it could be iOS if Apple starts selling physical keyboard iPhones and I find I really like iOS, or it could even be webOS or Blackberry 10 (or equivalent) if either gets dramatically more apps and in the case of webOS, new devices actually exist. (I also recently bought an HTC TouchPad and have found I like webOS quite a bit, more than Android OS but maybe not as much as WP OS.)