In programming world, heightweight frameworks or tools (such as EJB) are gradually replaced with lightweight ones (such as Spring or even Ruby on Rails). Anyone who experienced such kind of transformation will tell you "What a relief!"
How about testing world? When at the conferences, often off the stage, after feeling comfortable, serveral audiences would share their issues with their heavywieght automated testing tools: Super Expensive and Not Working!
Then one day, one Job Ad captured my attention:
Job: Test Analsyt - Selenium & Lightweight testing tools
"... build lightweight test automation harnesses using Selenium and other testing tools (not QTP however)."