I love Google Tasks, been using it since Google released it in 2009 May. I have also used many, many, many other get things done (GTD) app but keep coming back to Tasks for its simplicity and ubiquitousness.
Even tried to replace Tasks with Google Keep but the latter doesn't work out so well as a GTD app for me. I do suspect that Google will kill Tasks eventually and in its place setup the "Reminders" section of Google Keep. If they did this, and replaced the Chrome Tasks Extension as they did when they replaced the Talk Chrome extension during the rebranding of Talk into Hangouts - I would be all in.
Having an extension which is always there and easily accessible is better then navigating to a web app. Otherwise, I will just continue using Keep like a note taking service and Tasks as an actual GTD. Much in the same way as Notes and Reminders for the Apple folks - maybe Google is just emulating that.