You mean in MW3 right? Have they stated the score per amount-of-time in it yet? Cuz I don't know lol. And maybe it would make sense, except since killstreaks are now point streaks, Support Class packages might benefit too much from it and they may feel it overpowered.
I'm not sure, but that may be just them, and hell, they can and might just release updates later that change whatever score we get from HQ and all else.