Andy,
Great. It is mostly about checking if the code is clean, if it follows lsst coding standards; we also use it as a vehicle to learn from each other. You don't need to do any verifications whether it works, this is up to the person writing code. We try to keep reviews lightweight, e.g. an hour or two, but sometimes we break this rule and end up with monster reviews, like CSS. The name space review should be quick, I hope.
I'm sure KT will chime in about the review process :-)
Jacek