I taught in a laptop school several years ago. The technology was JUST maturing then, but most of my problems were person-driven rather than technology-driven.
Here are my tips
1) Firmly establish who actually owns what, because that determines the scope of your reach. If the computers are still school property, you have a lot more reach than if the kids buy them up front or buy on an installment plan.
2) Either way, you're going to have to amend your Acceptable Use Policy to address issues brought up by the laptops. I would do some research into other laptop schools and download their AUP. In fact, contacting other laptop schools is probably a good idea in general. It's always better to make your first mistakes vicariously through someone else.
3) Partition the laptops so that user data is stored on a separate partition, and invest in a good disk-imaging system. You're going to be imaging a lot of laptops after a few weeks. No matter how hard you lock them down, someone is going to screw something up so royally that you can spend 6 hours fixing it or 10 minutes imaging the disk, and it will happen frequently (how frequently depends on school size). In fact, you may want to get clever and make 3 partitions. 1 main, 1 user data, and 1 unmounted that holds a local copy of your image file. Image your main partition only, copy it to your "hidden" partition, and image the whole thing for deployment.
4) Figure out a theft-protection mechanism. This will eventually become an issue. Laptop insurance/warranties will also be an issue. If 15% of the laptops begin malfunctioning near the end of a 4-year-run, that will be enough to make it difficult for teachers to rely on those machines for classroom exercises. Nothing it more frustrating than having a whole lesson plan come to a stand-still because 4 kids' computers won't work. I've had it happen to me plenty of times. These also tend to be the kids who don't need any additional distractions.
5) If these are school-owned laptops, then you have a great deal of latitude in locking them down. Remote monitoring is another issue, and I would consult your district's attorney. As far as locking them down, the guiding question should be "what level of security supports the curriculum." Most slashdot users will think of these laptops as computers, with all of the implied potential. Thus any lockdowns curb that potential, and in turn the student's freedoms and opportunity. While this is a valid mode of thinking for personal machines intended for personal purposes, it is the wrong mindset to have in an educational environment. For starters, most students will never come close to tapping that potential (they want to surf the web and IM).
These laptops are being purchased to augment your curriculum, and should be configured in a way that makes it a platform for your curriculum. This may involve lots of restrictions, or just enough to keep a kid from accidentally breaking something. While you'll probably learn as you go, you should already have some idea of where that line is. If you don't, I'd recommend more research and consultation/training your teachers before writing that big check.
With totally unlocked computers, it is likely that a significant portion of the machines will begin malfunctioning due to user-abuse: "I'm going to install every piece of crap software I find! Isn't it great?" While it won't be a majority, it will be enough to make it difficult for teachers to rely on the machines to function properly during an activity (see above).
