"Water resistant" not "water proof", the sealed keyboards are a variety of weights and key travels, and after Christopher and his team test them, they will do a larger test with K-12 students.
Tests of keyboard without CAPS LOCK keys!
While these keyboards are not end-production models, and each country will be able to offer customized keys in its preferred layout, the lack of CAPS LOCK keys at this stage is a strong sign that this time around, Nicholas Negroponte will not need to toss keyboard designers in jail.
CAPS LOCK Update!:
In his keyboard post comments, Christopher Blizzard says:
"Yep, the CAPS LOCK and the other *LOCK keys are gone. A lot of other things are going to change on the keyboard, but those aren’t coming back."