Pro Most of the features found on Jenkins are also available for Hudson
Since Jenkins and Hudson share much of the same code base, they also share many of the same features. Hudson is also very easy to install: there is simply a single .war file which is run inside the root of the directory where Hudson will be installed.
Con Superseded by Jenkins
Jenkins is a fork from Hudson and therefore inherits most of it's source code. But Jenkins has far more commits and is a lot more active on the development side than Hudson. A lot of plugin developers have also chosen to support Jenkins and develop their product for Jenkins only.