I think a 7" tablet from a reputable supplier will tick all the boxes for a lot of people and should do well, but if they price it in iPad territory or higher I think it'll struggle, and relying on carrier subsidies seems to be an uncomfortable area for tablet buyers - just look at how the Dell Streak has failed to set the world alight...
Let's not forget that the iPad was widely touted as being around the $800-$1000 mark by all kinds of 'experts', analysts and pundits before Steve Jobs dropped the $499 bombshell back in April. I'm sure Samsung will pitch the Galaxy at whatever price they feel it'll do best at, when it becomes available.
Cheers, Pete