You listed that the phone is very hackable as one of the selling points, and anyone who looks at the dizzying array of ROM threads on XDA for this phone will have to agree. It is the premier phone for development at this time, in my opinion.
With a little effort, anyone can find a ROM/kernel combination on the Thunderbolt that will provide acceptable battery performance, though it will never be excellent like the Charge. I am currently on Imosyn's 3.01 test kernel and das BAMF 2.0.6 and was at 13.5 hours yesterday and 38% charge when I decided to plug it in. That's just ordinary phone/text usage without any game playing or Netflix activity so YMMV. I have been on numerous ROM/kernel combination that have given me as-good or better performance. In fact, all of the das BAMF Froyo ROM's gave me better battery life, but I can't give up the Sense 3.0 elements or Netflix for that.
I've got an upgrade on another phone that I'm pondering right now so I've been looking hard at the Charge and Revolution, along with DX2 and D3 that's supposed to come out around 7/7. Of course there are many question marks around the D3, but we're pretty sure it's going to be 3G only, so that really hurts it in my book. The Revolution is interesting I admit as I'm a fan of LG products, but it's under-powered and under-featured and simply looks lame next to a Thunderbolt running Gingerbread. They do have CM7 though, so good for them.
The Charge is also a contender, but other than the screen and battery life, it doesn't impress next to the thunderbolt, and it has the two big problems of mediocre performance and feeling and aging like a cheap phone. I know some of you probably still have Charges in perfect condition, and I'm the kind of person who can keep a cheaply built phone looking good as well, but I would much rather have a brute like the DX or at least one that's extremely well-made like the Tbolt.
Anyway, hope that helps. If I had to buy another phone today, it would be a Thunderbolt. My daughter's birthday is on the 30th though, so I think I'll hang tight and see what develops between now and then.