With Bamboo Specs feature, available in Bamboo 6, you can reuse any aspect of your plan.

+1 here as well. This would be very useful for us.

@atlassian - is there a plugin to make tasks\scripts shared or can we build one?
please point me in right direction someone? as I understand, plugin can be built with Java, right? from Atlassian point of view - is it possible to build such plugin if we dig the API deep enough?
thanks.

+100500 on this! Just signed up to request this feature.
we have around 10 deployment projects (microservices) and each has around 30 environments (2 envs per client, staging+prod, and we have many clients which are growing!) so each time I need to change a common task in deploy project, i have to iterate manually through all envs! we even started to use "iMacro" chrome plugin that automates form filling and such, when we do some of these "massive" iterations on all environments....

I think this feature is a must, for big companies who have plenty deploys.
(btw our devops bosses already start pushing to move our stuff to jenkins... jenkins is already heavily used in other departments, but i don't want to migrate to jenkins.. and Bamboo is a great tool, just needs more development)

alright alright alright, my worthless vote has been cast.

+1 I agree with @richard.cross by 100% !!! I not want use Jenkins or Hudson but all of this can do described simple functions

Additionally, I would like to see common tasks between environments in Deployment Projects. Much of the time, deployment to environments is identical, save for the ${bamboo.deploy.environment} variable, yet I have to duplicate all of these tasks anyway!

+1 for this, as Bamboo is not quite yet what I would call a "Build Orchestration Tool" until Jobs and Tasks can be reused by other plans (with variables or input params driving their behaviour).

This is a sore point for me. We have dozens of environments and it is effectively impossible to manage without the ability to share common task configurations. As we still cannot rerun manual stages of a build, the deployment environments are our best hope, pending this issue.

We also have a lot of Tasks, which are the same across different Plans. That would be a great feature.