[lkillen]

The size of the DVM is directly dependant to the number and type of apps and frameworks you have on your phone. Apks are precompiled with the JIT and stored in the DVM. This makes the phone run much faster with less battery and memory drain (optimized).
Apps with heavy graphics will surely fatten the cache. But a big DVM will improve battery life as opposed to the alternative.
My cache was pretty fat and took sometime to clear but after I stripped down my phone, the DVM shrank with it. Today, I installed a different kernel and while doing so, clear the DC and it cleared instantly. But I had deleted a lot of the bloatware that came with 3.7 including that Nova game. Hmmm.... that may be the one

I could also imagine the HTC made a more intense optimizer in order to make the phone run faster and leaner. That woudl result in a bigger DVM.