From a spokesperson at Apple:

It will likely be years before you need to replace it (1000 cycles at 200 cycles/year = 5 years). You can have the battery replaced at any Apple Store or Apple-authorized reseller. The replacement battery is priced at $179, which includes installation of the new battery and environmentally-responsible disposal of the old battery.

The non-removable MacBook Air battery costs $129 to replace, though the lifespan is not promised to be as great. [Apple]

The 17" MacBook Pro is basically a supersized 15" with an Air no battery bottom, which is at the least aesthetically pleasing. But with no battery compartment there is now no way to easily change Ram or Hard drive. So have your #00 Phillips ready.

The unibody construction makes the machine feel much more compact when picking up and overall condenses the already thin casing. It does indeed feel heavier than any other MacBook model but that's to be expected from a 17" casing. The trackpad has also been updated to the same no physical button pad found in the other MacBook models and even though the 17" MacBook Pro is bigger the trackpad has not grown.

The 17" Glossy LCD looks crisp as it did on the previous version but the new black plastic border makes colors pop just as it does on the 15" Pro and 13" MacBook. For some reason apple is only showing the regular glossy LCD model today so we can't yet report on the new anti-glare model.

Overall the new 17" MacBook Pro with unibody construction is nothing we haven't seen from the other models in the MacBook line. With the 15" MacBook Pro look and the Air's no battery bottom the new 17" MacBook pro can now stand proudly inline with its smaller siblings.