Firstly, i would thank wamp team for there amazing efforts and devotion to the project
I have few suggestion which i think will allow to two or more wamp installation on single operating os...
Each version to have its own service names eg: wampapache20h & wampmysqld20h and other requirement independently. So user can user use newer or older version without removing the old version while other wamp server versions are stopped/not running status.
Thanks.