Atlassian has just announced the Bitbucket Pipelines Beta for Bitbucket Cloud, which let your team build, test, and deploy right within Bitbucket, giving you end-to-end visibility from coding to deployment. At the same time, Atlassian has announced the end-of–life for bamboo Cloud, which implies that Tasks for AWS will remain a server only solution at this point:
We believe that the best way to provide our customers with a top-notch cloud CD solution is to build the service natively within Bitbucket Cloud. That’s why we built Bitbucket Pipelines and also why today, we’re announcing the end-of-life for Bamboo Cloud, which will be discontinued starting Jan 31, 2017. While Bamboo Cloud has helped many customers to adopt CD, we realized that we would not be able to deliver the experience and the quality of service that our customers need. If you’re a Bamboo Cloud customer, click here to learn more about the migration options.
If you want to build and ship behind the firewall, we’re still heavily investing in Bamboo Server as an on-premise CD solution.
We'd very much like to support Bamboo Cloud (formerly OnDemand) too and are getting more respective requests recently. However, Atlassian doesn't allow classic add-ons to be installed in their cloud offerings for security and scalability reasons, rather only those build with the new add-on framework Atlassian Connect - ironically Connect doesn't yet support Bamboo in turn, so unfortunately we cannot do anything about it at this point and rely on Atlassian closing this gap first - see Managing Bamboo Plugins:
NB: while acknowledged as such (though the phrase eventually suggests an implementation to be unlikely for the time being), the issue has been closed by Atlassian on 2014-10-1 for reasons I do not agree with and it isn't possible to vote anymore accordingly - it is still possible to comment, so please make yourself heard to hopefully change their mind about this issue's priority.
Fortunately Atlassian seems to have reconsidered and reopened the feature request on 2015-04-15.