I'm glad someone else asked the question. My contract is up on my original Droid at the beginning of December. My power button just broke, and rather than fix it, I am making due and going to spend my money on a new upgrade. I was about to get a Bionic this week but once I read about the couple new ones coming out, I'm waiting. I've never had anything but Motorola phones, so I don't know how the HTC or Samsung brand reputation is. In reading a few replies, it would seem both phones will be the same, but one will be more basic and update faster. I don't root my phones, but just use them as they come out of the box, and add my favorite apps. Hopefully there is a clear cut better phone coming in the next month or so I'll be happy.
If you dont root your phones but do like to tinker with them as far as changing the overall appearance then you may really like the HTC. Sense has it all when it comes to customizing a non rooted phone.