As the Gmail Blog states,
We've been continually improving Tasks since it first launched in Labs. We believe simple and fast is best, so we've been working to make Tasks more responsive and get basic interactions working better: we've added mobile and gadget views, made improvements to task editing and management, launched in more languages, and integrated with Google Calendar. We've also added a printable view for those people compelled to do things away from their computers or mobile devices.
Personally, I never used Tasks, but since this is now a standard add-on for all Gmail accounts, doesn't look like I have a choice, eh? But oh well - atleast we now know that there will be more graduates from the Gmail Labs. Good going, Tasks! Well done!