Congratulations! I received mine in the post on the 27th.
I also entered the country on a student visa, but in August 2005. I got married in June 2007. When it comes to filling out that form, I will be using the day I became resident in the UK, which is the day I arrived on my student visa as, since that time, I've only been out of the country on holidays. In other words, I've been a full-time resident of the UK since the day I arrived in August 2005...I guess I haven't looked at the form lately. i didn't thnk it asked about when you intended to make a long-term commitment, but rather, when did you become resident.
MTA: Just took a quick look at the application and guide, but don't actually see any reference to what you've mentioned or what I've mentioned! It just wants you to have been in the country for a specific period of time and to give the number of days you've been out of the country during that time...