Completely Replace Outlook Tasks with Planner.
Outlook tasks are outdated and have tons of limitations. REPLACE Tasks with Planner. Include Planner as part of all O365 plans offering Exchange Online. People who use Outlook with Exchange Online should get the Planner Version of Tasks. This to my mind would kill all competition in the mail client + task management areas across all devices.
Planner lacks a lot of capabilities that Outlook Tasks have starting with all the different views, first class support of start date instead of due date, full desktop experience e. g. for attaching documents or mails into tasks, quick actions like "Create task with mail attached" which cost me only one click in Outlook today, ...
Paul Thexton commented
Optionally would be fine, but fundamentally I would like to see the planner view from Outlook directly. As a standard workflow I always have Outlook open for internal communications, having to log on to Office365 on the web does not fit with my current workflow (nor anybody elses that I know of).
I think the planner would be so beneficial to my department, but I agree with Keith it should only be as an option.
Keith Budurka commented
I only support this if it was optional. On or Off (less complex) would be OK. I just know how many people in my Org use TASKS today and have mastered them. A change like this would change their world (and not in a good way - until they can relearn how to work this)