I bought the collector's edition so I'll be getting the DLC with my order...
That said, I fully understand why so many people are angry over this issue. If it were your average henchman DLC character like Zaeed or Kasumi, then none of this would be a problem because ultimately, they are just "another" henchman.
But a PROTHEAN?! Protheans are a race of alien that went extinct 50,000 years ago after the last Reaper invasion (it's going to be interesting to see how Bioware explains the existence of a living Prothean) and are of great importance to the lore of the Mass Effect Universe.