If you want to learn how to use a video camera and lots of manual controls, go with the HMC 40 without a doubt.
DSLRs are nice and all, but they are not video cameras. They lack gama curve settings, b press, coring, ect.
The HMC 40 is a far more customizable (Im actually not 100% sure, but I am pretty sure it has all of the scene file settings that panny cameras do) and you will learn how all of that cool stuff works and what it means.
t2i has its purpose and it wouldnt be terrible to go hand in hand with your hv40, but I do not think you will regret the decision on the HMC 40.
After learning the HMC 40 and what all the settings mean and do, then I recommend getting the T2i.
T2i is a GREAT camera and I love mine, but I can never sell my HVX (unless I get something similar) and I can never be happier with my decision buying one mostly because what I have learned from using it.
Hope that helps. Seems like you want to get into film making and understand that HDSLRs have their purpose and should be used as a tool in the tool kit rather then entirely on their own.
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