Just thought I would throw my hat into the ring here and add a comment. First of all, if this deal does include all WP7 devices including the Titan it wouldn't be a hit to AT&T. I mean have you looked at your bill lately? Even if you are a single person you are most likely paying northwards of $70 a month with a smartphone plan. That means they are making AT LEAST $840 a year off of you using their services. Another thing to note this is just a one day deal and its while supplies last. This means that they would still make money the day after and every single day after that. Also, the cost to build a WP7 is not that much. In fact, that's what they were touting in their presentation this year was how significantly lower their cost to manufacture was over the competition.
@Blacklac
I would be surprised if you keep your unlimited plan for this upgrade. The problem is that most of the people that have unlimited data were on the 3G plan. When you upgrade to a 4G device, for some reason in their computers it's listed as a 4G plan so they automatically enable the 2GB or 200 MB plan. If you know someone at AT&T that is smart enough to know how to get around it, great. But, at least where I am at, they get new employees every month and they don't know what the **** they are doing.
On a side note, have you looked at your monthly bill? Are you really using more than 2GB? I thought when I had my unlimited taken away that I would go over it every month but I haven't yet. I mean they dramatically cut your speeds after 2GB anyways that the internet is pretty much unusable.