It's funny how some people *cough*Imperium Alpha*cough* actually get off by people having trouble accepting something. Actually it's sad that this is the highlight of his day, but oh well not all people have friends in RL.
Anyway, I think that day 1 DLCs are wrong in the first place, I remember when I bought Baldur's gate II and what I got for the price I paid. Back then if I convert it to €, I paid about 35€ for a HUGE game I thouroughly enjoyed and when an expansion pack came, no one complained and many bought it, because it brought an additional value to the game. The problem with most people don't seem to be that a character is included in this DLC, the problem seems to be that it's a Prothean because the lore in the game makes them incredibly important. So it may just be, that the problem is just a poor choice of character's race, I doubt complaints'd be this many if the character was another Turian or a Human.
What makes it even worse, the explanation given by Bioware, which does try to calm down its fans is a bit of a critical miss too. Some fans feel offended by "a true fan will have a CE anyway" because it's simply not true. From what I know (not my case) some people saved up their scholarships to buy Mass Effect 2 when it came out, a regular edition, and gave their money with pleasure, trusting in Bioware... Then they bought DLC's for it too because it gave just what I mentioned before, ADDITIONAL VALUE. You have to remember, for some of your fans 50€ means chosing between your game and something else, not all people live in conditions in which they can just say "oh screw it, we'll just buy everything", so the "true fans are CE" is just wrong. And while this character apparently being in a leaked script (I don't know, I didn't read it) is really not a deffinitive proof that he was intended for a full game it does prove he was in some serious considerations and that you guys probably wanted him to be a part of a full product and saying otherwise makes you loose credibility of your fans, you have to know they are angry and even saying something that is just half a lie makes them believe it's a straight on blatant lie. And yes, maybe now you will earn more money with that DLC, sure, but then again what about long term? You will have some mighty dissapointed fans, if the Prothean turns out to be a dissapointment of a character then from people who paid for the expansion and if he turns out awesome and even a little bit important for the story then from others. Believe me, coming from C&C community getting fans back on your side is TOUGH, after what your collegues pulled with the 4th installment of our beloved franchise there is still such resentment from the fans you wouldn't believe.
This may be TL;DR to many but yeah, guy look you still have much respect from gaming community and you are one of the rare developers to have that luxury. Like I said, the DLC character may just be a poor choice of race, but long-term is it really worth alienating and not only that, splitting your fanbase on two sides, over this character, you yourselves label as "not important for the story"? Then give the people who will buy this first day DLC I still think is just wrong, I mean come on start milking the game on the first day, real nice, something else. Soundtrack was mentioned and I'm sure it would be a nice addition. Will I buy ME 3? I have it pre-ordered at one of our stores so yes, but remember a good reputation is worth more long-term than making your community and loyal fanbase thinking you've abandoned your good bussines practice.