Each year at the end of January the celebrities and statesmen of the world meet in Davos and for that time you will not be able to book any room directely in your hotel of choice, BUT have to do so with a special agency that will most probably NOT accept ordinary people for that time at all. I was in Davos to apply for a job and was told that not even the hotels will know except a few days in advance, who will stay in which hotel. There will be the Putins, Bushs, Clintons etc. and a lot of security-people spread all over Davos and ordinary tourists will not even be able to take a walk through the village.
The main street becomes One-way near the Convention Center and if you are not careful (like we weren't, cause we were looking around as we entered the village) you might find yourself driving against all others!!! :D
Beware of getting close to the place on the famous Davos Summit days. No, the place does not become worse itself and, if you are a law-abiding person, you've basically nothing to fear from the security services. Unfortunately, not everyone is law-abiding, and you could run into some Black Blocks or other brand of violent anti-globalization protesters, and I dare say that would be an unpleasant meeting, for you at least.
Also, on a less dangerous (for your health and property) note, the prices (already not the lowest in the world) tend to go up quite sharply with the arrival of many distiguished guests...
So, my best advice is: Check the summit schedule in advance!
When going up in the Alps, bring some warm clothes with you. Mountain weather is unpredictable, and you never know when you will need a pair of gloves, a hat or dry socks...
Oh, and wear your helmet!