If you really wanted to get a .cloud name, make sure its a work that goes with cloud computing. You will find most of the good keywords are already taken so you will need to pay a bit more to get a good name that makes sense (Live.Cloud, My.Cloud, Storage.Cloud, Data.Cloud etc)
If you arent sure of what strong keywords are, this thread might help a bit. They have to be words that make sense in the front of teh word cloud as well
Don't forget that "cloud" is also used in other languages so no, good keywords are not already taken In French, we translate "le cloud" for "the cloud" for example.