Lets see here. Amnesiatic hero joins those who caused his amnesia against big bad guy who was once student, but then gets betrayed by one of those who caused his amnesia, but continues to kill bi bad guy and saves day. Yeah, we seen that a thousand times. REALLY!
Okay, the betrayel thing is a Biowarian schtick they have used before (NWN1), used again (JE), and probably reuse again and again (ME and DA). As well as the trial with 5 judges thing (NWN1), which they reused over and over (KotOR and JE), and they will probably use in future games (ME and DA). And the arena fighting idea that they used in KotOR and reused in JE, which I wouldn't be surprised if they use it again in ME and DA.
I don't mind games not being overly original but at least don't flaunt the fact you aren't going to be original.