This phone will be harder to crack than the captivate (there was already a lot of work and knowledge gained from work on other galaxy S devices, plus we now have a locked bootloader to contend with. BUT, I think that this phone's amazing specs will attract people on XDA, so my money is on them to crack it open.
That said, I have a captivate. I hated touchwiz, wanted to do wireless tethering, wanted to get stock Froyo, didn't want all the at&t bloatware, etc etc etc, so I rooted and flashed a great ROM. However, I really wish I didn't have to void my warranty every time I get an AT&T cell phone. It's getting tiresome, and I'm worried about the eFuze thing... with the captivate, 99% of the time if you made a mistake while flashing, you could go into download mode and reflash the phone, but now I think it will be riskier. I think I'm going to talk to some Droid X owners and see how safe they feel about flashing and rooting their phones with the eFuse. I guess it all depends on how well the devs on XDA can make a reliable, easy to follow guide / software program that will unlock this beast.
Come on XDA... I'm counting on you guys...
As soon as the project is underway I will be a big donor (well, like 20 bucks - I don't have a lot of money), and I suggest that everyone else on this thread does the same thing. Support the devs that make these things possible; it isn't easy and it takes a lot of time, they deserve our support.