Currently the Nunit Runner task is only capable of running in build projects but it would make sense to allow it to run in Deployment projects as well. Here is a use case:

I would like to do these actions in this order:

1. Build my solution
2. Run unit tests
3. Deploy to staging
4. Run Integration/Acceptance tests on deployed software through NUnit
5. Deploy to production
6. Run Integration/Acceptance tests on deployed software through NUnit

If the NUnit runner task would be available in Deployment Projects then this scenario would be trivial.