From what i am aware of this will most likely not happen unless they are able to optimize the size of the file. It is a big file and would hog a lot of your resources. Rom developers are able to trim the fat (metaphorically speaking) since they are optimizing it to the best of their ability and taking out a lot of the bloatware that Sprint puts on it as well as optimizing the images and other software things.
After using the DInc does Desire Z rom, I must say that it is really nice and I love the flip clock. Also the added themes give it the ability to customize the look without having to flash a theme. Lets cross our fingers and hope that HTC releases it for all of their current top devices.